Summer Vegetable Gardening in the Deep South: The Best Vegetables for a Southern Summer Garden

Imagine the hottest day you can imagine, with humidity in the 90s. These conditions are stressful for humans, so of course, they are stressful on garden vegetables. Most tomatoes and corn stop pollinating at temperatures above 85 degrees, while squash and cucumbers fall victim to borers and powdery mildew.

There are some iron-clad, no fail vegetables that you can grow in the scorching heat of a southern summer. While they are not foolproof, they will withstand most of the onslaught of heat and humidity. If you only have a limited amount of space, these are the southern garden vegetables you should grow.

Okra – Okra is the best of all of the summer vegetables. A distant relative of Hibiscus, it absolutely loves the conditions in a southern vegetable garden. While it may be susceptible to powdery mildew if conditions become too humid, it is one of the easiest crops to grow in the south. Clemson Spineless is a favorite of all southern gardeners.

Southern Peas – Black-eyed peas, crowder peas, and purple hull peas grow very well in a southern vegetable garden. They can be picked green, or left to dry on the plants for dry storage.

Butter Beans – Memories of sitting on the front porch, shelling butter beans is something that southern families treasure. Lucky shellers were usually rewarded for finding speckled beans, but always knew that this was a ploy by their parents to get them to work. Jackson Wonder and its beautiful purple speckled beans are a southern heirloom favorite.

Peppers – Hot peppers and sweet peppers seem to enjoy the heat. Bell peppers may need to be protected from the hottest afternoon sun to prevent scorching, but many others do not. Jalapenos and habaneros seem to soak up the heat and spit it back out into your mouth.

Eggplant – All varieties of eggplant thrive in the southern vegetable garden in the summer. Ichiban and Black Beauty are perennial favorites, while the milder white eggplant is growing in popularity. Be sure to pick them when the skin is still shiny, or they will be bitter.

Cherry and Grape Tomatoes – While regular slicing tomatoes won’t pollinate, cherry and grape tomatoes grow like crazy in the heat and humidity. Sweet 100 and Tommy Toe are two favorite heirloom varieties.

Pole Beans – Kentucky Wonder is an heirloom vegetable favorite that can’t be beat. Not only do they grow well in the sweltering heat of a southern vegetable garden, they are prolific and generally pretty trouble free.

While frustrating at times, southern vegetable gardening can be immensely rewarding. If you grow nothing but these lucky seven vegetables, you will have a vegetable garden any southern gardener would be proud of. When all your spring planted vegetables wither and fail, these faithful standbys will fill your stomach and even your freezer.

Three Tips for Organic Vegetable Gardening: Learn to Grow Vegetables Without Chemicals

Many people imagine that organic vegetable gardening is difficult. It’s actually easy to begin growing vegetables, fruits and herbs using organic methods. These three tips will get you started to a beautiful organic vegetable garden.

Build Soil by Adding Compost

Compost is often called black gold by gardeners, and for good reason; it’s a rich organic source of nitrogen, phosphorous and potash, the three major building blocks of soil, as well as many trace elements. You can purchase compost or make your own.

To make your own compost, simply find a spot in your garden away from the house or use an old trash can. Begin adding kitchen scraps from fruits or vegetables, such as carrot peels, potato skins, browned lettuce leaves, and apple cores.

Add some soil from the garden to encourage beneficial bacteria to begin breaking down the plant matter. Add leaves in the fall or grass clippings in the spring and sprinkle with water or allow the rain to soak the compost pile to further encourage bacteria to break down the materials. Turn the compost pile regularly.

When you see crumbly black soil under the refuse, that’s compost. It can be added to the garden frequently. The more compost you add, the better the vegetables, since they will use the compost to build healthy roots, leaves and flowers. Never add animal waste or animal products. Animal waste may add parasites, and scraps of meat, fish or poultry will only attract vermin to the compost pile.

Animal manures may also be added to the soil as natural compost. Horse manure, cow manure, chicken and goat manure all make good fertilizers for organic gardens. Be sure to let them age, since fresh manure is very high in nitrogen and may burn plant roots. A safe way to incorporate manures is to add them to the compost pile, turn them in, and wait until they crumble down into soil.

If you see worms in your compost pile, don’t panic – celebrate! Worms actually eat through all the leaves, grass clippings and apple cores and poo out the rich dark matter gardeners know and love as worm castings, one of the richest fertilizers available. Worms are an organic gardener’s best friend, and finding lots of worms in the compost pile or garden is a sign that it’s a healthy organic ecosystem.

Use Companion Plants Such as Marigolds to Discourage Insects

Before commercial pesticides, gardeners relied upon nature to teach them how to repel insects. Some plants are both beautiful and useful. Marigolds, for instance, repel many insects. They naturally repel tomato horn worms. Tomato horn worms are several inches long and bright green. They will strip a tomato plant of all of its leaves in a single night. Marigolds planted around tomatoes will naturally repel these voracious bugs.

Basil is also another wonderful companion plant. Many gardeners also plant basil around tomatoes. It is known to repel white flies and other insects.

Numerous other companion plant combinations exist, some tested and some only tested by time. For the organic gardener, harnessing the power of natural to naturally repel insects reduces or eliminates the need for commercial pesticides.

Rotating crops in your vegetable garden also reduces the incidence of insect pests. Some insects lay eggs in the soil which hatch the following season. If you rotate crop groups, such as cruciferous vegetables and squashes in the same bed from year to year, the insects won’t be able to find food. You will greatly reduce or eliminate them by making it hard for them to find their next meal.

Neem Oil and Organic Pesticides

Some plants are difficult to grow through preventative organic methods without using some kind of fungicide or pesticide. Roses, for example, often get black spot, mites, and a host of other diseases.

When it becomes necessary to use some sort of topical pesticide or fungicide, choose an organic product. Neem oil, for example, is taken from the neem tree, and works wonders to repel pests ranging from black spot to Japanese beetles.

Diatomaceous earth is an excellent organic pesticide if snails or slugs are chewing away the leaves of your vegetable plants. Diatomaceous earth is a powder created from the ground up remains of diatoms, creates with a hard shell. Sprinkle the powder around vegetable plants.

Although you can safely handle the powder, and it won’t harm animals or birds, the tiny little crushed up shells destroy the soft bodies of slugs. Using beer traps by placing a small pool of beer or a beer bottle tilted sideways to allow slugs to crawl in and drown happily in a puddle of beer also provides organic control methods that won’t harm the environment, animals, birds or beneficial insects.

When starting organic vegetable gardening, the amount of information on organic gardening may seem overwhelming. Focus on building your soil and the battle is half won. Harness natural pesticides like marigolds to repel insects. And if invaders threaten, use only organic products like neem oil. Enjoy the fruits of your labors with a clear conscience knowing they are chemical-free organic vegetables.

Growing Seedlings Indoors for Flower and Vegetable Gardens

Seeds have a few basic requirements if they are going to grow into healthy, vigorous garden plants. Luckily, they are simple and fairly easy to satisfy. First is adequate light, followed by water, warm soil, good air circulation, and food.

Let There be Light

Most seeds don’t need light to germinate, but once they’re up and growing make sure your seedlings receive 16 hours of light daily. Give seedlings too little light, and you’ll end up with spindly, leggy plants. Seedlings can tolerate up to about 18 hours per day.

While it is possible to produce healthy seedlings on windowsills, most gardeners start seeds in winter when days are short. For this reason using artificial light or supplementing natural light is best.

A simple shop light—ideally connected to a timer to turn it on and off automatically—is a good place to start. Ordinary fluorescent lights are fine. More expensive grow lights don’t necessarily produce better seedlings.

Whether you have a single fixture or a plant stand with tiers of lights, use chain and S hooks to hang the lights and make them adjustable. To give seedlings maximum light, adjust the fixtures so the bulbs remain 3 inches above the leaves. After the first few weeks, raise the lights and keep them 4 to 6 inches above the leaves.

Moisture and Warmth

Seedlings need even soil moisture and high humidity, but remove any plastic covering seed flats as soon as seedlings appear. Otherwise, damping off, which rots the stems at the soil line, can develop. Running a small fan ensures good air circulation and further reduces problems with damping off.

Temperatures between 60° and 70°F suit most seedlings. Temperatures above 75°F usually result in leggy, weak seedlings. Plant preferences vary, though, so check seed packets for recommendations.

Lettuce, cabbage, and other cool-season crops prefer cooler temperatures. Soil that’s slightly warmer than the air speeds germination and growth. The easiest way to provide this is to set plants on a heat mat specially designed for growing seedlings.

For best results, check your seed flats daily. Most seedlings need evenly moist soil that is never too wet or too dry. Letting the soil surface dry out slightly between watering helps reduce problems with diseases like damping off, but be sure to check seed packets for individual requirements, since some seedlings require constant moisture.

To determine if seedlings need watering, stick a finger into the soil or lift the flat to see how heavy it is. (Once you’ve lifted a newly watered flat, along with one that hasn’t been watered for a couple of days, you’ll be able to judge how much a flat weighs when it needs watering.)

When pots do need watering, water gently and use warm water, since cold water can shock the plants. It’s easy to flood seeds and newly germinated seedlings right out of the pots.

Use a watering can with a rose that delivers a fine sprinkling of water or deliver water gently out of a water bottle with your thumb covering most of the opening. Watering pots from below is actually best, since it protects seedlings and helps prevent disease problems. To water from below, set pots in a larger container or flat filled with water, and let the water soak up to the soil surface.

Food for Seedlings

Seed leaves, the first set of leaves a seedling produces, provide all the food the plant needs to germinate and grow until the first set of true leaves appear, which resemble the mature leaves of the plant.

If you are growing in seed-starting mix, once plants produce a set of true leaves, water them weekly with a liquid fertilizer such as fish emulsion mixed at half the recommended strength. After 3 weeks, switch to full strength. Seedlings growing in ordinary potting soil or a mix that includes compost may not need feeding for several weeks. Feed them if the leaves seem to turn yellow.

Raising Seedlings Right

Once your seedlings are up and growing, clip off all but the healthiest one in each pot with scissors. Or, transplant them to individual pots. Otherwise they compete for space and nutrients. When transplanting, handle seedlings by holding a leaf, never the stem, since it’s very easy to crush. To ease their transition to the garden, harden them off first by gradually exposing them to more direct sun and outdoor breezes.

Start by setting plants out for an hour or two in a protected spot. Over a few days extend to leaving them out overnight. Water thoroughly before and after moving plants to the garden. Ideally, transplant on a cloudy or rainy day or shade plants with upturned bushel baskets or burlap suspended on sticks to further ease the transition to the garden.

Indoor Gardening: Playing in the Dirt with Kids: Children Love to Watch Plants Grow Indoors and Out

The groundhog saw his shadow and pronounced there would be six more weeks of winter. Don’t worry, though. You can still get ready for spring. Bring the potting soil inside and help children prepare for the growing season.

There are many garden plants that can be started inside and others that grow quickly enough to satisfy childish needs for more plants now.

Collect Materials

Buy a bag of potting soil and sweeten it with nutrients from your compost heap or add crushed leaves. It is also good to mix potting soil with a little of the soil from your yard. Vegetables you start inside will be planted outside eventually and getting them used to the native soil helps them thrive. If you don’t have compost or the yard is still frozen, these extras aren’t essential, so read on.

Peat pots from the store are good because you can transfer your plants grown in them directly to the garden. However, there are many good pots that you can save from the landfill for awhile. The clamshell plastic boxes that grape tomatoes and other vegetables are packed in make great garden boxes. You can also cut about 3 inches off of the bottom of plastic milk jugs or other milk or juice boxes to create planters.

Buy seeds from the hardware or garden shop. You’ll also need small shovels or spoons to scoop and dig in the dirt.

What Seeds to Buy

Tomatoes that sprout from seed and grow from a few inches and up to a foot tall by time to plant outdoors are great to get started now. Tomatoes are one of the easiest garden vegetables to grow indoors from seeds. Herbs started indoors now will be nice-sized seedlings for planting outdoors in a month or two.

However, young children might want to see results quickly. For fast results, try mung beans, sunflowers, radishes, lentils, and peas.

Plant, Water, Watch

Spread paper on the floor and get to work. Fill pots with dirt. Talk to kids about how deep to plant the seeds. Determine the seed-planting depth from the seed packet and use a Sharpie to a quarter or half inch line on the child’s finger. Allow them to poke a finger in the dirt to the prescribed depth, and then insert the seed. Fill in the hole over the seed.

All seeds and plants love a little drink of water to get started, so allow kids to water their plants. Set pots in a sunny location. In a week or two, the kids will be excited to see progress. In another month when all chance of frost has passed, they can insert the peat pot or seedling into an outdoor garden.

While waiting for sprouts to appear, read books about healthy eating and find recipes that will allow your young gardener to make something fun and nutritious for lunch!

Fig Facts

Talk about an heirloom fruit. Figs (Ficus) have been around almost forever. The California Fig Advisory Board (CFAB) claims figs were mentioned in a Babylonian hymn book from about 2000 BC.

We all know that fig leaves were used as clothing in the garden of Eden. CFAB claims the fig is mentioned in the bible more than any other fruit and that figs were probably one of the first fruits to be dried and stored by man.

Technically, the fig is not really a fruit. It’s actually an inverted flower, or multiple fruit, enclosed in stem tissue instead of ovary tissue. Botanically this is called a syconium. Only the small seeds would be considered fruits. The fig completely ripens and even partially dries while on the tree, without falling off. You’ll know a fig is ripe when it begins to droop on the branch.

The tree itself is a rather coarse-leaved, shrubby looking deciduous plant, anywhere from 10 to 30 feet tall. A native of Asia, figs can be made at home in any warm, dry climate. Propagation is generally done by cuttings of 2-3 year old shoots, although grafting is also popular.

Harvest season is usually early fall. If you’re going to find a fresh fig, that’s when to look. However, since figs naturally dry to some degree, they can be packaged and sold throughout most of the year. I should state here that I have been looking for a fig all week and I have not found one.

Perhaps they were all scooped up for the Thanksgiving holiday, but I suspect there weren’t that many to begin with. The fig is an old fruit, but its popularity has been higher. It has been the subject of renewed interest, probably because of marketing, and after years of turning up my nose at figs, I decided to give them a try.

Fig trees could not survive in my climate, yet there are people who grow them. Some bring them indoors and under lights for the winter. Others perform the amazing feat of burying the whole tree and then digging it up again in the spring. This is something to see. I think that’s what convinced me to try figs. If someone is that passionate about a fruit, it must have merit! Figs are one of the best sources of fiber, among fruits and vegetables.

Garlic – A Great Way to Start “Seed” Saving

Garlic may be haute cuisine today, but it took a while to establish itself as a staple seasoning. Most of today’s “boomers” rarely encountered garlic while growing up. If they did, it was probably garlic salt or powder from a jar that sat in the cabinet for years. Times have changed and garlic has become respectable, even medicinal.

Garlic is a member of the allium family, originally believed to be from the mountains of Central Asia. It has been around for centuries as evidenced by pictures of it on the ancient pyramids. Most garlic is planted from bulbs and therefore an heirloom of sorts. Because garlic does not cross pollinate and rarely even sets seed, it is a very easy vegetable to start “seed” saving. Of course, you needn’t save seed at all, since you will be growing from cloves. The hardest part will be convincing yourself to save the largest, finest bulbs to replant.

There are basically two types of garlic: hardneck and softneck. Hardneck garlics (Allium sativum var ophioscordon ) produce a stiff flower stalk topped with small bulbils or mini garlic bulbs. This flower stalk is called a scape and should be removed to encourage the underground bulb to grow. Hardneck garlic produces a bulb with one layer of large cloves. The removed scapes are perfectly edible and full of garlic flavor. They will become somewhat tough and woody if left to mature, so it is best to harvest them as soon as a curl or loop starts to form. The hardnecks varieties you are likely to come across are: Purple Stripe, Porcelain and Rocambole.

Softneck garlics (Allium sativum var sativum) are a cultivated and more widely adapted variety, although less hardy. They no longer produce scapes and the tops stay pliable. These are the varieties that you will see braided for storage. The bulbs themselves generally have more cloves than the hardneck varieties, although smaller in size. However they make up for their lack of size with greater productivity and more layers of cloves than the hardnecks. Softneck sub-varieties fall generally fall under the two varieties: Artichoke and Silverskin.

The garlic varieties available to most of us in supermarkets pretty much all looks the same. But there are over 600 cultivated varieties of garlic in the world. Growing and taste testing varieties is your best chance at sampling the subtle differences and finding one that grows and keeps well in your area. Seed catalog are beginning to offer more and more varieties.

Old Fashioned Gardening: Testing Soil Using the Senses

Using the senses can be effective testing methods in checking for successful gardening soils. Sight, smell, feel and touch are the most economical methods.

According to the earliest records of farmer’s journals, the senses were the best tools for testing soil. The pH, dirt type, and quality of soil determined what could be grown and the outcome of a harvest. A farmer tasted for pH levels, observed by sight the color of the soil, determined by other natural plants and smelled the soil for purity.

A more complete and accurate analysis can be made by engaging a local agricultural extension department and investing in kits and services. Litmus paper can also be used for pH testing. However, for the home gardener, the old fashioned practice using the senses, can provide a pretty good estimation for where to plant certain plants and what nutrients or soil amending is needed.

Checking the Color of Soil

Color tells a gardener a lot about the soil for water filtration. Dark and rich soil is the ultimate wish for every gardener. This soil is considered loam or humus and will hold the water in a desired amount. Yellow-gray sandy soil drinks and filtrates the water quickly leaving plants thirsty and dying.

To reach this desired level, thickly mulch soil with about 4 inches or more with dried leaves, wood chips, garden clippings or other organic material. This technique will trap moisture and nutrients around the roots of the plants and build the soil.

Note that in tropical, rain forest type regions, composting with wood chips or dried leaves could bring on termites. Check with the local agricultural service for the best practices in soil enrichment.

Smelling the Soil for Freshness and Richness

Smelling the soil can unveil secrets about prepared soil from a garden shop or other places. Top soil that is mixed with compost should smell fresh and not moldy, but not so fresh that it has a ripe manure or sour smell to it. Overly fresh manure will burn the plant roots. However, if fresh manure is added in the fall, tilled well and left to winter, the nutrients will be ready to feed acid loving plants. Note: Check plant soil requirements and place acid sensitive plants in recommended soils.

Observing Nature for Soil Type

Check the local library for weeds, trees and plants that grow naturally. For instance: Clay soil yield chicory weeds, buttercups, sorrel and thistles. Natural hawk weed grows in dry areas and clover thrives in compacted and poor soil. Cat tails survive in wet and boggy soils. The best soil for garden success supports ground ivy.

Soil acidic pH indicators are dandelion, dock, horsetail, lady’s thumb, and sorrel. Iron weed, penny cress, pepper grass, sagebrush, and woody aster grow in alkaline dirt.

Tasting the Soil

This is a not so recommended or desirable method of checking for pH in the soil. E-coli and other bacteria could be lingering there. But it was a widely practiced activity of our ancestor farmers. The gardener of yesteryear, and some brave and die hard farmers, such as perhaps the Amish of today, may still taste for alkaline or acidic dirt. Acidic is a sour taste and alkaline is sweet.

Using the Touch Method

A seed packet for one vegetable or flowering plant may recommend a more sandy soil, others may recommend loam, clay or humus rich or well-drained soil. Soil that is well aerated to give roots a deep path to moisture and nutrients will be loose, but not so loose that the water drains away the nutrients. If a soil has too much clay, the sun will bake the soil into bricks.

Running the fingers through the dirt, picking it up and tossing it out to the wind and feeling the grit or moisture can give a good indication of the type of soil needed for a particular plant.

Gardening by Science – Soil Texture

Plants have very simple needs. They must have food, water, light and air. They also need support, adequate space, and a host of living and decaying organisms to grow and reproduce.

Soil provides support, a large portion of the food necessary for a plant’s growth and is home to fungi, bacteria, earthworms and other creatures. It also provides protection. All these things are very much like the house you live in and like that house, a comfortable and healthy home goes a long way to maintaining the health and well-being of its occupants.

What Type of Soil Do You Have?

Soil can be described by its color, crystalline structures, the amount and type of organic material in it, and its texture. Soil types come in various sized particles and are generally categorized into three types. The texture of your particular soil is the total percentages of each of these types:

  • Sand – large particles,
  • Silt – smaller particles but still visible to eye,
  • Clay – flattened microscopic particles,

The ideal garden soil will have an even mix of all three and is called loam. It is a dark brown, almost black soil, crumbles well in your hands, with some stickiness and has lots of organic material in it.

It smells earthy. Loam holds water and nutrients but also has good drainage. Before you begin planting, you should complete a comprehensive analysis of the particular area that you will be planting. This should include an analysis of location, water needs and soil sampling.

Methods of Soil Texture Analysis

As a homeowner you have several options to determine the soil texture of your yard or garden soil. Observation of the types of plants already growing on the soil can indicate the type that you have.

These plants are called indicator weeds. Good examples of indicators for clay soil are dandelions, chicory and coltsfoot. These plants will grow profusely, sending down deep roots that help to pull up nutrients and break up heavy or compacted soil.

Taking soil samples and processing the samples at home or sending them on to a reputable laboratory is another way. Samples sent on to a lab will be more accurate and will give you a lot more information than you can get with your home sampling. So what’s the point in all this science?

The Importance of Soil Texture

Water moves through soil by means of gravity, pulling it down and through the soil particles. During this flow, the water absorbs nutrients and creates a vacuum behind it which then pulls in air from the surface. Some of the water in the soil attaches to the soil particles.

This provides necessary moisture to roots and allows living organisms to feed and move about. Particle size – the texture of the soil – plays an important role in water flow, replenishment of fresh air and nutrient availability.

Soil that contains a high percentage of sand is not able to absorb water. Nutrients that were taken up by the water are leached away. Because the particle size is large, there is less total surface area for the water to adhere to, thus there is less available moisture and nutrients available for root systems and organic processes. Plant growth is reduced or may not occur.

Silt particles, though smaller in size than sand, also can be affected by leaching. In addition, the smaller sized particles are slippery. Soil that has a high percentage of silt may result in runoff problems. Water and nutrients do not make it down to the root zone because they have been washed away on the surface.

The structure of a clay particle is different than sand or silt. It is flat, forming massive layers. It absorbs and holds most of the water that flows into it. The particle size is so small that it can become heavy and compacted to the point that little or no air or water gets into the soil. The soil can become dead such as blue or white clay soils. Soil that has a high percentage of clay tends to compact but can be very fertile.

Using the Science

Whether you are planting a vegetable or flower garden, putting in a natural landscape or a lush green lawn, you don’t have to be a scientist to understand the importance and characteristics of soil texture. But, you can use the science to help you plant what will grow best in the type of soil you have.

Organic Container Gardening Soil – Preparing The Pots

Organic container gardening soil is not the same soil you use in your non-container garden. The soil from the ground is often too heavy for use in containers. The soil compacts to quickly which results in poor drainage and poor plant growth. Prepare your pots with a light soil that is free from disease and weed seeds.

Preparing the Pot

Your first step in preparing the pots for the organic gardening soil is choosing the right containers. Remember to plant in containers that are at least one-third the size of the mature plant. Once you have your containers, ensure that there is adequate drainage.

Most terra-cotta pots and commercial planters have holes in the bottom for drainage. If necessary, drill extra holes around the bottom edge with a ¼-inch drill bit. Your pots do not require many holes, but you want to be sure the water does not simply sit in the soil and cause root rot.

Preparing a Drainage Base

Once the container is full of soil and the plant, often it is not moved. For this reason you want to ensure that the drainage holes do not get clogged with the organic container gardening soil. A good way to prevent this is to use pea gravel.

Pea gravel is small stones and is available at home improvement centers or plant nurseries in bags. Pour a 1-inch layer of pea gravel evenly in the bottom of your container. The soil sits on top of the pea gravel and the gravel allows the water to drain sufficiently through the container.

Organic Container Gardening Soil

There are special organic blends of potting soil available at home improvement centers. You might also choose to use compost as a soil for your containers.

Many people opt to make their own organic container gardening soil, especially if they have many pots to fill. Mix together one part potting soil, one part sand and one part compost. Add some peat moss to aid in moisture retention and some organic perlite to help with drainage.

Fill the containers to within 2-inches of the top rim. This allows room for mulch after planting. Prepare all of your pots with your organic container gardening soil of choice within a week before you plant your seedlings and seed.

The soil will have an opportunity to settle and warm to the surrounding temperatures. Mix your soil slightly before planting to allow oxygen into the soil and break up any compacted areas.

Make Garden Water Stickier with Oil and Soap: Surfactants make Pesticides and Fertilizers More Effective

Water is an essential element in gardening. The problem with water is that many times it doesn’t stick or penetrate as well as one would like. To get water, or anything mixed with water, to stick or penetrate more effectively, something must be added.

What Kind of Adjuvants are Oil and Soap?

There are several different types of agricultural adjuvants. Oil and soap act as surfactants. Surfactant is a blend of the words Surface Active Agent, and was coined by Antara products in 1950.

How Do Surfactants Work?

Surfactants change the surface tension of water, making it “wetter” or “stickier”. Surfactants influence the wetting and spreading properties of liquids, and change the precipitation, suspension, and dispersion of another substance in the water.

In layman’s terms, surfactants make whatever you mix with water disperse into the water and break down into smaller particles so that it spreads better on the surface. When the liquid is sprayed onto a surface, the surfactant makes it “stick” to the surface.

Type of Surfactants

The three types of surfactants are nonionic (no electrical charge), anionic (negative charge) and cationic (positive charge). Soaps and oils are anionic surfactants.

How Oil and Soap Are Used as Surfactants

There are two uses of surfactants in the home garden: to allow agents to stick to the surfaces of plants, and to make water stick to the soil.

  • If pesticides do not stick to the plant surface for a long enough period of time, the insects will not be affected. In this circumstance, oil and soap act as extenders, which are surfactants which increase the period of time a substance remains on a surface.
  • Soap breaks down the waxy coating on the bodies of some insects, allowing the insecticide to penetrate their hard outer shells. Oil seals the pores on the bodies of insects, causing suffocation.
  • Adding soap to liquid fertilizer when using foliar feed prevents the fertilizer from running off of the plant, and also allows what does run off to stick to the soil around and under the plant, increasing the availability of the fertilizer.
  • In soils that are very porous or sandy, where it is difficult to get the soil to hold water, soap added as a surfactant causes the water molecules to “stick” to the soil particles, thereby increasing the amount of water absorbed by the plant roots.
  • In soils with a high surface tension, where water stands on top and doesn’t readily absorb into the soil, soap breaks the surface tension, allowing the water to be absorbed.

Surfactant Usage Rates

When using commercial products, always follow label instructions to the letter.

When using household products to make homemade pesticides, many recipes can be found online. One good recipe is 1/3 cup Oil Soap (like Murphy’s), 1 tablespoon baking soda, and 1 gallon of water. The baking soda acts as a fungicide as well as changing the pH to a more alkaline mixture.

Cautions When Using Surfactants

While soap and oil sound relatively safe, there are some cautions you should use:

  • Never spray any mixture containing oil during the hot part of the day, as it could burn your plants. Always spray in the early morning or early evening.
  • Do not use laundry detergents, or grease cutting dishwashing detergents, because they contain additives that counteract the surfactant properties of the soap, or that may be harmful to plant life.

Using surfactants is green and thrifty. It is a simple way to make your gardening products more effective, while also saving money.