July marks the start of fall planting in the gardens at Southern Exposure. We’re located in zone 7a, and while July may seem too early to be thinking about fall, it’s essential to give crops plenty of time to mature before autumn’s cold weather arrives. During July, we’re working on getting brassicas like cabbages and broccoli transplanted. 

We always get questions when folks see them on the planting list during one of the summer’s hottest months. If you’ve ever wondered how we work with cool-weather crops in hot weather, here’s some advice.

Choose Fall Varieties

The beauty of open pollinated and heirloom crops is that they offer unique traits. Gardeners, farmers, and seed savers have bred some varieties specifically to tolerate the hot dry weather of late summer to produce a bountiful crop.

Some of our favorite fall brassicas:

• Waltham 29 Broccoli
• Early Flat Dutch Cabbage
• Savoy Perfection Cabbage
• Snowball Self-Blanching Fall Cauliflower
• Snowball Y Fall Cauliflower
• Red Rubine Brussels Sprouts
• Catskill (Long Island Improved) Brussels Sprouts

Collards and kale are also great choices for fall brassica crops and perfect for direct sowing. They are quicker to mature, cold hardy, and collards are easy to grow in areas where it’s too hot for good cabbage production.

Collards

• Champion Collards
• Georgia Cabbage Collards
• Georgia Green (Georgia Southern, Creole) Collards
• Granny Hobbs Collards
• McCormack’s Green Glaze Collards
• Purple Ultracross Collards
• Variegated Collards
• Whaley’s Favorite Cabbage Collards
• White Mountain Cabbage Collards
• William Alexander Heading Collards

Kale

• Lacinato (Dinosaur) Kale
• Lacinato Rainbow Mix Kale
• Premier Kale
• Vates Kale
• White Russian Kale

Time Your Plantings

Timing fall plants can be tricky. Plant too early and you’ll have broccoli trying to head up in the hot weather of late summer or early fall. Plant too late and winter will arrive before your crop matures. 

To plan your plantings, you’ll need to know your average first frost and your crop’s days to maturity. Count back based on your days to maturity from your first frost. 

However, you also need to keep in mind that plants grow more slowly in the fall as the day length dwindles. To take this into consideration, you want to add 14 days to the days to maturity time for any variety you’ll direct sow and 14 to 28 days for any variety you will be transplanting. This longer period helps account for setback and transplant shock. 

Transplant Well-Developed Seedlings & Harden Them Off Carefully

Transplanting in any season can be rough on plants, but it’s even worse during the hot summer months. Good quality soil and attention can help you grow well-established seedlings that will better tolerate transplanting.

Before you set your plants out, it’s essential to harden them off. This means that you slowly adjust them to the temperature, sunlight, and wind outdoors before planting them out in the garden. Start by setting them out for just an hour or two each day out of direct sunlight and then slowly increase the time and sunlight exposure over a couple of weeks.

Learn more about hardening off here. 

Keep a Thick Layer of Mulch Around Plants

A heavy layer of mulch will insulate the soil. It keeps the soil cool and holds in moisture. It also suppresses weeds, which will compete with crops for water and nutrients. Add at least two inches of mulch and add as necessary to cover bare or thin spots as the mulch breaks down.

Water Consistently

Cool weather crops need a steady supply of moisture to grow well in late summer. Try to water deeply 4 or 5 times per week as they’re getting established. Check the soil frequently to make sure it stays moist.

If possible, it’s best to water in the early morning or evening. These cooler time periods will allow more moisture to seep into the soil before evaporating.

Offer Shade if Possible

Shading crops, especially when they’re first transplanted, can reduce the stress on your seedlings. You can use shade sails, easy-up pop ups, or low-tunnels with lightweight row cover. Whatever you choose, it’s most effective to position it so that it provides protection from the harsh afternoon sun when temperatures are highest.

If available to you, low tunnels are likely the most versatile, easy-to-use option. They also provide protection from insects like cabbage whites. As summer gives way to cooler temperatures in fall, you can swap out your shade cloth on the tunnels for a lightweight row cover for additional frost protection.  

As a new gardener, I always hated those articles that were like here’s five full proof crops that any beginner can grow. I’d see wonderful success with tender plants like heirloom eggplants and tomatoes only to have supposedly “easy crops” like bush beans turn to lace when I didn’t notice the bean beetles in time. Sweet corn is one of those crops often touted as easy to grow, but it’s not immune to issues. Here are a few of the common problems I see with sweetcorn and how you can prevent them.

Poor Sweet Corn Germination

The first issue you could run into is poor germination. Sweet corn seeds last a few years when stored properly. If your seeds are more than a couple of years old, you can also use an at home germination test to determine your seeds germination rate.

However, even if you have good quality seed, it’s possible to have germination issues.

The first issue that I like to eliminate when I see corn that’s not coming up is wildlife. Corn kernels are a tasty snack for wildlife, like crows, field mice, and squirrels. If you don’t get good germination, look for signs of soil disturbance, and dig up a few kernels to ensure that they’re still actually there. You may have to hang up deterrents like aluminum pie pans or place netting or a protective barrier over the bed to keep wildlife out while your corn is just starting to grow.

Wireworms, which I will detail in the pest issue section below, can also destroy seeds before they germinate.

Cool, damp conditions can also be problematic for sweet corn germination. Sweet corn seed requires a soil temperature of 65° F or warmer to germinate well. In cool soil, the seed rots easily because of its high sugar content. Don’t rush your first planting; wait until after your first average frost-free date.

If you don’t have a soil thermometer, you can use a traditional indicator, old-timers say to plant corn when the oak leaves are the size of squirrel ears. Another old country saying is that you can plant sweet corn when you can sit with your bare bottom on the soil comfortably.

Pest Problems

Sweet corn is susceptible to pests like cutworms, wireworms, earworms, and corn borers.

Wireworms and Cutworms

Wireworms are the reddish brown larval stage of click bugs and cutworms, usually in shades of gray or brown, are the larval stage of various moth species. Both pests spend their time hidden beneath the soil. Wireworms will eat and destroy corn seed and the roots of young seedlings, while cutworms will eat through the stem of young plants.

While I often advocate for low till or no till agriculture, tilling your soil can actually help reduce cutworm and wireworm populations. Running chickens or ducks through the garden for a few days before planting can also help. Over time, practicing cover cropping, crop rotation, and adding beneficial nematodes can also be effective.

Corn Earworms

Corn earworms are true to their name. They feed on the developing ears, starting at the tips. Suffocate them by inserting a medicine dropper half filled with mineral oil into the silk after it has wilted and browned at the tip (4-5 days after silk appears).

Corn Borers

Corn borers also have an appropriate name. They bore through the corn plants and ears, eating as they go. They can destroy ears or even weaken entire crops. You can prevent them by composting corn refuse and stubble as soon as possible.

Wildlife

In high school, I got my first job at a local organic vegetable farm. While I was helping to sow the enormous field of sweet corn, the owner explained to me they plant more than they think they’ll need. He said, “when you grow sweet corn, grow a third for yourself, a third for the raccoons, and a third for the deer.”

Sweet corn is highly attractive to wildlife. Your corn patch may tempt birds, deer, raccoons, and even black bears. Fencing is a good option for keeping out most wildlife. Including multiple wires of electric at different heights can help you block a range of animals. Motion activated lights, noise-makers, and sprinklers can also help deter wildlife.

Growing Conditions

Sweet corn is a heavy feeder that does best in nutrient rich soil with plenty of moisture.

Nutrient Deficiencies

Nutrient deficiencies can cause stunted growth and poor production in sweet corn. Often you’ll notice leaf discoloration.

For example, nitrogen deficiency causes yellowing leaves, typically starting at the tip and progressing down the midrib. Phosphorus deficiency often causes purpling, especially in young plants, and potassium deficiency frequently causes browning on the leaf edges.

Adding compost to the bed and providing adequate spacing can help prevent these issues. You can also get a soil test and use techniques like crop rotation and cover cropping to build healthy soil over time. Side-dressing plants with manure from your own livestock or fertilizer can help address immediate issues.

Drought

Drought can cause stunted growth and poor production. In low moisture, you’ll often notice wilting or curling leaves.

For best production, mulch corn in well once it’s established. Sweet corn thrives with 1 to 2 inches of water per week, so irrigate as necessary.

Sweet Corn Diseases

Corn is susceptible to a few diseases, which can negatively impact production.

Northern Leaf Corn Blight (NLCB)

NLCB is a disease caused by the fungus Setosphaeria turcicum. It thrives in areas with high humidity and temperatures between 65-80° making it a common issue for Southeastern growers in the spring.

You’ll first notice it causing elliptical tan or gray spots or lesions on the leaves starting near the base of the plant. These can be 1 to 6 inches long. As the disease progresses, they can darken and appear water-logged.

If your plants get NLCB before they silk, you will probably have low production.

If you struggle with NLCB, it’s probably worth switching to a resistant variety like Bodacious RM – sugary enhanced hybrid Sweet Corn.

Southern Leaf Corn Blight (SLCB)

This disease is caused by the fungus Bipolaris maydis. SLCB thrives in hot conditions with temperatures between 68-90°F. It can be a major problem in the Southeast, particularly in the late summer and fall.

Like the northern blight, SLCB will create lesions on your corn’s leaves. However, these lesions are smaller, typically only one inch long, and are usually surrounded by yellow halos.

SLCB can kill your plants, especially seedlings.

If you struggle with SLCB, try a resistant corn variety like Silver Queen.

Corn Smut

Ever seen ears of corn with large, puffy gray masses on them? That’s corn smut. It’s a fungus that forms during dry, hot weather. Corn smut is a delicacy in Mexico, but if you want corn rather than corn smut, remove and destroy the fungus; otherwise the black spores will re-infest your corn for several years.

Poor Pollination

Corn is primarily wind pollinated. The male tassels release pollen which is carried on the wind to the female silks. Each strand of silk corresponds to a kernel on the ear. If a silk isn’t pollinated, it will not form a kernel and you’ll end up with ears with big gaps.

If you’re not growing a large field of corn, planting in blocks is better than long rows. For good pollination and well-filled ears, plant in blocks at least 5 rows wide.

If you have a situation where you think your corn may not be pollinated, hand pollinate yourself. Ideally, you want to pollinate your corn in the first 4 to 5 days after silk emergence when the tassels are shedding pollen. The silks are still receptive to pollen up to 10 days after emergence, but to a lesser degree.

Hand pollinating corn is simple. Use scissors to cut off a few tassels and gently brush them on each ear’s silk.

 

 Want to save seed from your plants? Check out our post, 8 Easy Steps to Save Corn Seed.

Tomatoes are the queens of the summer garden, but they’re not problem free. Avoid these common tomato mistakes for a bountiful harvest this summer.

Not Planting Properly

Tomatoes are among the toughest transplants we grow, but proper planting technique is still essential to getting them off to a good start. 

Timing

Timing is critical for tomatoes. They’re sensitive to cold temperatures, so you need to wait to transplant until after all danger of frost has passed and the soil temperature is at least 60°. Waiting until the soil has reached 65° to 70° is ideal.

While not thought of as a succession crop, you can also plant a late batch of tomatoes. You’ll need to time these transplants so that they have plenty of time to mature before your first fall frost. 

In late summer and early fall, the short day length and cool temperature slow plant growth. When you’re planning your planting date for tomatoes, add 14 to 28 days to their days to maturity to account for this slow growth.

Spacing

Proper spacing is also an important consideration when planting tomatoes. It’s hard to picture those tiny transplants turning into the giant plants they grow into by the end of the season. However, your plants will produce better if they’re given the space they need. For good airflow, moisture, and nutrients, space tomato seedlings 12 to 18 inches apart in rows 3 to 4 feet apart.

Depth

You should also transplant your tomatoes to the proper depth. Tomatoes thrive when they’re buried deep. Pinch off your transplants bottom set of leaves and then transplant your tomato so that the next set of leaves is just an inch or two above the soil. The section of stem that you’ve buried will send out roots, helping your tomato plant to adapt quickly and taking adequate water and nutrients.

Pruning Incorrectly

Pruning tomatoes can be a great way to increase airflow and mitigate the risk of certain fungal diseases like late blight. However, improper pruning technique can set back growth and reduce your harvest.

Only prune indeterminate tomato varieties. Never prune determinate varieties. 

To prune your indeterminate tomatoes, look for spots where the main stem and a branch create a V-shape. In these V-shaped notches, you will notice new small branches growing. These new branches are called suckers.

Suckers will usually flower and produce fruit. However, they can make your tomato plant unruly and harder trellis. They also reduce airflow and can affect your harvest quality. Plants will spend energy producing new suckers and fruit. While that sounds great, it can reduce the overall size and quality of tomatoes as the plant’s energy is further divided. 

Inconsistent Watering

To grow a large harvest of high-quality tomatoes, your plants will need consistent watering. Tomatoes thrive with about one to 2 inches of water per week. This can be a combination of rain and irrigation or one of the two, depending on the weather.

Inconsistent watering with periods of heavy drought or high moisture can reduce yield and quality. Plants that receive inconsistent water are prone to issues like blossom and rot and splitting. 

Splitting in tomatoes is often caused by a relatively dry period, followed by a period of heavy moisture. When your plant goes through a dry period and then receives a ton of moisture from rain or irrigation, the fruit will rapidly swell and expand, creating cracks in the skin.

Blossom end rot is thought of as a fungal disease, but it’s actually caused by a lack of calcium as the fruit is developing. Calcium deficiencies in soil aren’t very common, but when your plant doesn’t have enough water, it cannot take up the calcium that it needs.

Over-fertilizing 

Tomatoes love having fertile soil, but you can’t have too much of a good thing. Get a soil test before fertilizing. If your garden already has adequate nutrients, adding fertilizer can do more harm than good.

When tomatoes receive excessive levels of nitrogen and other nutrients, they put on more foliar growth rather than fruit production. They can also be more prone to pest and disease issues.

Excessive fertilizer can runoff or leach from your bed into nearby ditches, streams, and other waterways. Once in these waterways, the high levels of nitrogen, potassium and phosphorus can create toxic algae blooms, which are harmful for people and wildlife.

Finished compost can be a safer way to give beds a quick boost of nutrients. Learn more about when to fertilize your garden here.

Harvesting Late

We all get busy in the summer and it’s often tough to keep up with the garden when we’re balancing other family and work obligations. However, you’ll get the most from your tomatoes if you harvest often and at the right times. 

Ripe tomatoes should be the correct color for their variety and glossy. When you touch the tomato, it should be firm, but have a bit of give to it if you squeeze it gently. When you try to remove it from the stem, it should come off fairly easily.

If you wait too long to harvest tomatoes, they can over ripen split and rot, which can lead to pest and disease issues.

Growing tons of tomatoes is always a highlight of summer. Keeping these common mistakes in mind can help ensure you get a wonderful harvest.