5 Ways to Save Your Garden From the Heat

1. Water, Water, Water!

The most important part of garden maintenance in the summer is watering, the right amount and the right timing. When you water make sure you are watering deeply so that you do not under or over water your plants. If you wait till the soil is mostly dry for the first inch or two then water it for long enough that the water reaches deep into the soil, you will increase your plants drought resistance. Plants roots seek out water and nutrients so if the water is found near the surface of the soil, because the gardener isn't watering for long enough, than the roots will stay shallow and close to the surface. If instead there is plenty of water deep in the soil because the gardener routinely waters for a long period of time the roots will grow deep to access the water. As the gardener you can start by watering two times a week in the late spring but as the temperatures rise you may need to increase to four times a week to keep the soil damp. If you continue to water consistently and deeply you will keep a reservoir of water deep in the soil for your plants to pull from on the really hot days.

Timing is also crucial. It is best if you can get out into the garden in the early morning to water. This allows for the water to be absorbed by the soil and the roots before the heat of the day and it reduces water loss due to evaporation. You can also water in the evening when the sun is going down; just make sure that you avoid watering in the heat of the day. When you water while the sun is up you are more likely to burn the plants leaves and fruit with the water droplets, you will also waste water through fast evaporation, and you'll put yourself out in the heat. We recommend watering primarily in the early morning because watering at night can lead to sitting water, both on the plant and in the soil, which can in turn lead to increased pests and disease. If you check your garden to water in the morning you will also have a better idea if your plants need more water because you can look for wilting foliage. During hot days your vegetable's foliage will naturally look slightly wilted, this is completely normal and not a cause for concern or additional watering. Your plants should perk back up when the sun's intensity decreases. If your plants look wilted in the morning that means they need more water because they did not have enough to recover in the evening and overnight. So remember if you see some wilting at noon don't panic, if you see wilting when you check on your garden in the morning then its time to water deeply.

This is why something like an irrigation system can come in handy, because an irrigation system that lays on the soil will deposit the water directly into the soil without wasting water on the foliage and it is also much less labor intensive. You can go out to your garden and turn on your water then leave and do other things to allow for the water to makes its way deep into the soil at a slow but constant rate. Then you can come back and shut it off later in the morning. While your irrigation is running is also a great time to do a scout walk through your garden checking for pests, disease, or fruit and vegetables ready for harvest!

2. Plant Hot Plants

The best way to have a healthy garden in the hot season is to fill your garden with plants that can handle the heat. This means your summer garden will be made up primarily of plants in the solanaceae family (tomatoes, eggplant, peppers), the cucurbitaceae family (cucumbers, squash, zucchini, melons, pumpkins), legumes (all your beans), and a few other plants like sweet potatoes, herbs, okra, and corn. Make sure you have harvested or removed all your cool weather plants and have planted your hot weather plants before the weather gets too warm to give the new transplants or seeds time to establish themselves. If you have any young plants, like ones that were just transplanted, make sure to give them a little extra care as they will not yet have a high level of drought resistance or heat tolerance. 

Once you have chosen the hot weather plants you want to grow, look for local varieties or varieties adapted to your area. Not all plants, even warm/hot weather plants like a tomato or squash, have the same level of heat or drought tolerance. For example in Louisville Kentucky, where I am, if I want to grow a large tomato a good option would be Brandywine, an heirloom variety that is well adapted to both high heat and high humidity because our summers here can get very hot and humid. Cherry tomatoes are also a good option for hotter climates as most varieties of cherry tomatoes do well with high heat. Paying attention to the plants you choose and using plants that are  both hot season plants and adapted to your area will save you a lot of frustration and work, and will set you and your garden up for success. 

3. Plant Densely or Mulch

To help your plants retain water, you can either plant densely creating a full canopy over the soil or you can use mulch like leaves, grass clippings, pine leaves, and completed compost. A densely planted garden will shade the soil and reduce water loss. It will also create a sort of humidity chamber around the lower younger leaves and plants as humid air gets trapped below the leaf canopy. If you have open garden space you can fill it with flowers or herbs for a low maintenance filler. A layer of mulch reduces water loss directly from the soil and helps retain moisture at the soil level. It can also reduce runoff when watering and therefore protect your soil's nutrients. If you use a mulch then you'll want to layer it about 2 to 4 inches thick to be effective. Both options are effective; it's really up to you, but we highly recommend you use one or the other to reduce water waste and prevent plant loss in heat waves.

4. Take Care of Your Soil: the Foundation of Your Garden  

Take care of your soil so that your soil can take care of your plants. A healthy well balanced soil will do a number of things. Nutrient rich soil will give your plants all the resources they need to grow deep roots, and strong robust foliage making them ultimately more drought and heat tolerant. If they are damaged due to heat stress a strong plant in good soil will be able to rebound much faster, just like how a healthy human who eats well and drinks lots of water can recover faster from illness. Just like people, if a plant is already stressed, due to lack of nutrients, disease, or pests, it will be more susceptible to heat stress and will not be able to rebound.

Well balanced soil will both allow water to soak in deep and distribute the water evenly so that the all the plants roots have easy access to water. It will also evaporate slower from the soil when it is well distributed so the soil will not dry out as quickly. 

You can create nutrient rich and well balanced soil by starting out with a robust soil blend, then adding a fertilizer in-between seasons or adding other organic inputs like worm castings and completed compost. When you water deeply these nutrients will be carried with the water to all layers of the soil.

5. Invest in Some Shade 

If your garden gets intense sun when you might want to invest in some shade netting or cloths. A shade cloth can dramatically reduce the soil temperature and keep the sun off your plants if it's too intense. You can also use an opaque cloth to shorten the day by placing it at an angle to block morning or evening sun. These strategies can help you protect young plants or let you keep your cool/warm weather plants in the garden a little longer. You can use metal hoops or a square frame and some shade cloth over an herb bed to keep it from bolting or flowering. You can also plant in smaller containers so that you can use existing shade like your home or a tree and move the plants into the shade when the season turns too hot. What ever you use the shade cloth for, make sure you have a large enough frame so that the netting stays off your plants. If you have it resting on your plants, you might be saving them form the full intensity of the sun but you will be putting the stress of the fabrics weight on them which can stunt growth and harm them. 

Take Care of Yourself!

This is a bonus tip, take care of yourself! If you don't take care of yourself and get burnt out, then you won't be able to take care of your gardens. The heat can drain the energy and motivation out of even the most avid gardener so make sure you are taking care of yourself. That might mean only visiting your garden in the early mornings and evening and you really don't need to be in your garden in the heat of the day. It also means wearing the appropriate clothes to garden. Maybe invest in a nice hat for shade, I have a few go to ballcaps I like to use. Wear your sunscreen, you don't want your plants to burn or your skin to burn! Take it slowly in the garden and drink lots of water. Just like your plants, you also need to up your water intake in the heat. If you follow these tips above and take care of yourself, you'll find the hot season really isn't so scary and can be very productive!