Temperature plays a big role in determining what vegetables to plant in a garden. The seeds of some plants need colder soil temperatures to germinate while the seeds of other plants won’t germinate if the soil temperature is too cold. Certain varieties of cold season vegetables can survive light frosts while warm season vegetable plants need the temperatures to be above 50 or 55 degrees Fahrenheit, even at night. Cold season crops will go to seed or bolt, when daytime temperature climb to 70 degrees or hotter. Knowing what vegetables to plant and when to plant them is the key to a successful patio garden.
WARM SEASON VEGETABLES
Warm season vegetables include members of the nightshade family, such as peppers and tomatoes, as well as cucumbers, melons, and some types of beans. Warm season vegetables should be planted outdoors after the last frost in a person’s area.
Snap beans perform best in the garden when temperatures are between 60 and 75 degrees and should be planted in the garden after the last frost. The plants need soil that drains well. They also require full sun. The size of the plant at maturity depends on the type. Pole beans grow very tall and need the support of a trellis while bush beans are short and squat.
Sweet corn needs warm soil with an ample amount of nitrogen to thrive. The seeds won’t germinate if the soil temperature is cooler than 60 degrees. A gardener should mix compost into the soil when planting, then add nitrogen-rich fertilizer every few weeks.
Cucumbers need warmth, sun and ample moisture to produce an adequate supply of fruits. The plant can be either a bush variety or a vining variety. Vining cucumbers should be trained to grow vertically on a trellis, to help minimize the amount of space they take up and to keep the fruits from rotting.
Melons are related to cucumbers and have several of the same requirements. The plants need plenty of sun, warm soil and air temperatures, and an ample amount of food during their growing season. The plants grow to be very large and can be trained to climb a trellis. Types of melon include watermelon, cantaloupe, and muskmelon.
A gardener can grow either sweet, bell peppers in the garden or hot peppers. Both types of pepper need soil temperatures of at least 65 degrees Fahrenheit to produce fruit. Sweet peppers are more sensitive to extreme heat than hot or chili peppers, which continue to produce fruit in hot temperatures.
Squash plants include winter squash varieties, such as butternut and acorn squash, as well as summer squash varieties such as zucchini. Although called winter squash, the plants need warm temperatures to survive. They are called winter squash because it takes them until the late fall or early winter to reach maturity while summer squash are ready to be harvested early in the season.
Tomatoes remain a favorite for home gardeners. The plants need temperatures to be above 60 degrees for best results. Tomatoes also need full sunlight, soil that drains well, and ample fertilizer. Tomatoes can be determinate or indeterminate. Indeterminate tomatoes produce fruit and keep growing throughout the season. Determinate varieties reach a certain size and produce fruit all at once during the season.
COOL SEASON VEGETABLES
Cool season vegetables thrive in the colder temperatures of early spring and early to late fall in many areas. Vegetables that perform best in colder temperatures include members of the cabbage family as well as certain types of root vegetables.
A gardener can grow beets from seed directly in the garden in the early spring. The seeds should be planted about three weeks before the last frost in an area. The plants will thrive in temperatures that are well below 85 degrees F. Beets should be planted in an area that gets full sun daily.
Broccoli, and its close relative cauliflower, grows best when temperatures are in the 60s during the day. Higher temperatures encourage the plant to go to seed. The plant does best in full sun but can survive in part shade.
Cabbage seeds need cool soil temperatures for germination. Like broccoli, the plants perform best when the temperatures are in the 60s. The plants thrive in full sun and can tolerate part shade as the weather warms up.
Carrots thrive in temperatures between 55 and 75 degrees F. The plants need soil that is somewhat sandy and free of rocks or other debris. Rocks in the soil often result in oddly shaped carrots.
Warm weather makes the leaves of lettuce turn bitter. The plant itself bolts, producing a flower stalk and seeds. Lettuce does best when temperatures are below 75 degrees. A gardener can grow several types of lettuce, including loose leaf, which needs the least amount of space, and head lettuce, such as iceberg or bibb lettuce.
Varieties of pea plants include snow peas, snap peas and shelling peas. Both the seeds and pods of snow and snap peas can be eaten. Peas are one of the earliest plants, as they can grow in soil when the temperature is as cold as 45 degrees. The plants start to wilt and will stop producing once warm weather hits.
The ideal temperature for spinach is between 50 and 70 degrees. A gardener can plant spinach seeds directly in the garden between eight and four weeks before the last frost in the area. Spinach leaves become bitter as the plant grows older and temperatures become hotter.
Most vegetable plants are annuals, meaning they complete their life cycle over the course of one year or season. A gardener has to plant the vegetable again at the beginning of the next season. Perennial vegetables return year after year, meaning they can be less work for a gardener.
Asparagus is a cool season perennial vegetable that will return year after year for up to 20 years. The plant produces spears, which are either harvested by a gardener or left alone. If left alone, the spears grow into bushes that look like ferns. To help a plant get established, it’s recommended that a gardener not harvest the spears the first year.
Rhubarb is another perennial that thrives in cooler temperatures. The plant’s stalks are typically harvested in the spring. A gardener should leave the plant alone for the first two years of its life, and only begin harvesting the stalks in the third year.