Most vegetable gardeners know that certain veggies grow better in cooler temperatures.
Potatoes, broccoli, cabbage, peas and spinach are all plants that are planted early in our growing season because they are not affected, and in fact, they like the cooler temperatures of early spring.
What many gardeners may not know is that germination of garden vegetables is not hindered by warmer weather. There are minimum, maximum and optimal temperatures for seed germination for most plants. What you will find is that vegetable seeds are more inclined to germinate in warmer weather rather than cooler weather.
Also critical to your plants growing success are the temperatures after the plant has germinated and started growing. Each plant has growth stages that are heat sensitive. For example, many varieties of tomatoes will stop blooming and setting flowers when temperatures go above 95 degrees Fahrenheit and remain there.
If you want to germinate and grow vegetables when summer temperatures soar, there are some tricks for the gardener. To reduce the soil temperature, water the soil where you are going to plant seed, add mulch and shade the area where you are going to plant for several days.
Shade can reduce the ambient temperature by as much as 10 degrees preventing some plants from going dormant in high heat and allowing other plants to begin growing without heat stresses.
In a vegetable bed where plants are already growing, protect growing plants from the heat by also providing adequate water and mulch. Shade can be used successfully in several ways. Taller crops like corn can be grown where they will provide some late afternoon shade for other crops like peppers and tomatoes.
Shade cloths can be used to your advantage if they are high enough above the plants to allow proper ventilation. Heat can build up under a shade cloth without adequate ventilation which would be worse for the plants than no shade at all.
Shade cloths vary in density; they are designed to protect various kinds of plants from sun to shade loving. If you are using a shade cloth to protect sun loving vegetables, a less dense shade cloth would be appropriate.
Some seed companies such as Johnny’s Selected Seeds also provide information about heat tolerance of each plant on their seed packets. Look for this type information when you are planning and planting your vegetable garden so you can grow vegetables that will thrive in all seasons, even in the heat of summer.
Questions or comments related to gardening? Contact Joleen at missourigardener@hotmail.com.