The heat of July and August in Texas can be debilitating and can leave your garden looking barren and lifeless. For some plants the only option you are left with at this point is to give in to the heat and start over again when the temperatures fall back into a reasonable range. If you want to keep a productive garden over an extremely hot summer you will want to choose plants that thrive in heat and humidity. This guide will provide you with some options for maintaining a productive garden in an extremely hot climate such as Texas.
Before we discuss which plants to grow in the heat, we should discuss some overall strategies to promote healthy growth regardless of which plants you choose to grow:
Shade is your best friend when it comes to growing a summer garden in Texas. Just as we like to sit in the shade and sip on a cold beverage, your plants will also appreciate a good amount of shade as well. Even plants that are marketed as "full sun" will do fine with lots of afternoon shade. Try to shoot for at least 6 hours of sun for these plants, especially in the early morning and afternoon. Having an area that gets dappled sunlight all day is another option as well.
If you don't have any natural shade from the trees or structures on your property, you can create shade as well. If your garden area doesn't span several acres you can purchase a shade cloth to protect the most vulnerable plants in your garden during the hottest part of the day. Shade cloth can be purchased in custom sizes and is rated by the percentage of shade it provides. I recommend using a shade cloth rated at 50% shade for most vegetables, herbs, and flowers.
The reality of the situation is that you are no doubt going to have to water your plants often in July and August - sometimes every day. The timing of watering, as well as the method of watering, are both very important to minimize water loss to evaporation. Drip irrigation is highly recommended in garden plots in order to direct the water to the exact spot that you need it without losing a majority of it to evaporation. Watering with a sprinkler or by hand is not recommended if it can be avoided. The one situation when watering by hand is okay is if you are watering pots.
The timing of watering is also very important in order to maximize the uptake of water into your plants. Watering first thing in the morning before it gets too hot is the most efficient time to water. Your plants will be able to uptake as much water as they can before the heat of the day sets in and you won't lose as much water to evaporation. If you can't water first thing in the morning the next best time to water would be in the evening when the sun has made its way down and is no longer blaring hot. Watering during the hottest part of the day should be avoided if at all possible. If this is the only time you have to water then obviously it is a better choice than killing your plants.
Mulch is an extremely important addition to the garden no matter what season it is. Mulch protects the soil, prevents erosion, slows the growth of weeds, and acts as a temperature regulator. In the heat of the summer, mulch cools the soil and locks-in moisture. In winter, mulch warms the soil and protects the roots of your plants. We use a natural wood chip mulch at Ronin Farm, which provides great coverage and will eventually break down and add beneficial structure and fungal growth to the soil. Other options for mulch include: wheat straw, well aged compost, cotton hulls, pecan shells, and clean/weed free hay. Use a thick layer, at least 4 to 5 inches, for the best results.
Vegetables, herbs, and flowers to grow in extremely hot climates
Valentine's Day has come and gone and for me that only means one thing, it's time to plant potatoes! Okay, so I guess it means two things because it's also the day to shower my girlfriend with love and affection, but only after those potatoes are planted! I intended to publish this blog post much sooner, but Valentine's Day is also a very busy weekend for the farm and the restaurant and we have all been working extra hard to execute exceptional service for such an important occasion.
Choosing quality seed potatoes to start
The first step to planting potatoes in Texas is to source high quality seed potatoes. Seed potatoes are just like the potatoes you would see at the store, except they are usually certified to be disease free and they aren't sprayed with growth inhibitors. Planting certified disease free potatoes is important so you don't introduce something to your garden soil that will cause problems down the road. I usually buy my potatoes at Producer's Co-op in Bryan, or if I am looking for some more interesting varieties I will order them from PotatoGarden.com because they usually ship them at the correct time of the year. Some websites offer great varieties, but they seem to ship them way too late for those of us in Texas.
Preparing your seed potatoes for planting
Once you have acquired your seed potatoes the next step is to prepare them for planting. This involves cutting them into smaller pieces and allowing them to cure, or suberize, to protect them from rotting in the ground.
The trick to cutting the potatoes is to use a very sharp knife that is sterilized before use. The general rule of thumb I use is to leave the really small ones whole (about the size of a golf ball), cut the medium ones in half (the ones that are the size of a lemon), and cut the largest ones into quarters (the ones that are the size of an orange). You just want to make sure that each piece has at least two "eyes" on it when you are done cutting them. Once the the potatoes are cut they should be placed cut side up in a cool spot with good ventilation for at least 4 to 5 days, or until they develop a nice thick callus layer on the cut side.
Planting potatoes in the garden
There are a few different methods for planting potatoes in the ground. One of the most common methods is to plant them in a furrow and then mound up soil around the plants as they grow. I was taught to plant potatoes a little differently from a grower at Texas A&M, and it has always worked for me, so I continue to use this method each year. This method is to plant them extra deep in the beginning and cover them with soil once and be done with it. In order to do this you will need well-cultivated soil with good drainage. I recommend working in a few inches of well-aged compost into your beds to prepare the soil ahead of time.
Planting date: Mid-February to Mid-March
Plant spacing: ~12" between each seed piece
Planting depth: 10 to 12"
In this demonstration plot I dug down about 8" and planted the seed pieces with the eyes facing upward. Usually I would plant them a little deeper, 10" to 12", but I added an extra 2 to 3" of compost to the top of the row at the very end to make up for this.
After all the potatoes were placed into their holes, I used a rake to cover them up with soil. As I covered them with the soil I also added MicroLife Organic Granular Fertilizer to the soil at the recommended rate on the bag. Potatoes are heavy feeders and will perform better with good nutrition, which is provided by a great all-around fertilizer like MicroLife.
Once the potatoes were covered with topsoil, I added a 3 inch layer of well-aged compost over the row to increase the depth of the potatoes to that ideal 10 to 12" range.
Over the years I have found that potatoes need minimal irrigation for the most part in Texas. The spring rains that we receive are usually sufficient to produce good potatoes. There are specific times where you will want to make sure the plants do not dry out too much or else you will run into problems with misshapen or split potatoes. When the plant begins to flower this is a sign that the plant is going into it's bulking phase. This is the time when you want to make sure your plant is receiving a couple inches of water per week so it has sufficient water to form the tubers. Inconsistency with watering during this period can lead to deformed tubers.
Once the plants begin to start yellowing this is a sign that they are shutting down and the tubers are almost fully developed. The soil will still need to remain slightly moist during this period in order to preserve the integrity of the tuber, but watering can be reduced significantly.
If you plan to store the potatoes for a long time you can let the tops of the plants die back all the way and reduce watering completely for a couple weeks. This will cure the potatoes underground before you dig them up for storage.
You can harvest potatoes at different times depending on what size and texture you are looking for.
New Potatoes - New potatoes are the delicious, tender, and thin-skinned potatoes that are formed right after the plant starts flowering. Once your potato plants begin to flower you can carefully dig down with a soil fork and harvest some or all of the immature potatoes from under the plant. These potatoes won't store well because of their thin skin, but they are delicious if you plan to eat them within a week or so.
Storage potatoes - Storage potatoes are the mature potatoes that are dug up after the plant reaches the end of its life cycle. When the plant is finished storing starch in the tubers it will begin to turn yellow and wither. Once the plant dies completely you can dig up your fully mature potatoes. This can be accomplished by using a shovel or potato fork. Carefully dig underneath the plant from a good distance, because the tubers can grow outward as well as downward. You don't want to dig straight underneath the plant or else you may damage some of the tubers.
Once your potatoes have been dug, keep the soil on them and store them somewhere cool (50 to 60 degrees) for a week or two until the skins cure and harden. If you plan to store some of them long-term, the ideal temperature is 40 degrees and you will want to maintain 90% humidity. No matter how you store your potatoes, the most important thing is to keep them out of direct sunlight or else they will develop a toxic green pigment and will no longer be edible.
Growing potatoes in grow bags if you don't have a garden
For those of you who don't have a garden you can grow potatoes in grow bags on your patio or porch if it receives enough sunlight. There are potato grow bags you can purchase that are specifically made for growing potatoes, or you can buy some felt pots like the ones I have pictured below. The idea is to roll down the sides of the pot and plant the potatoes near the bottom of the bag. Once the plant starts to grow you can roll up the sides of the pot and fill in the bag with soil. Keep doing this until you reach the top and the plant is growing up above the top of the bag. I started a couple bags as an experiment because I have never done this before, and I will post a full blog post about it when I am done to let you know what I think about the process.
You will want to use most of the same methods as above for watering, fertilizing, and harvesting. Harvesting is much easier with this method though because you can just carefully dump the bag onto a tarp when you are ready to harvest.
If you have any questions about growing potatoes in your garden please feel free to send me a message, I would love to hear from you!
Recommended products for growing potatoes:
Written by Corey Wahl
Director of Farm Operations
Ronin Farm in Bryan, Texas