Even if the temperatures are scorching, late summer is a good time to start thinking about late season crops. Mustard greens can be plated at this time, letting you enjoy their spicy taste in a fall harvest.

Mustard greens are also an excellent addition to your diet. The University of Illinois Extension says they are high in vitamins A and C, fiber, calcium, potassium, and iron.

It is possible to start growing mustard greens in both spring and late summer. The gardening company Bonnie Plants says the plant will tolerate a light frost, which will help make the leaves taste sweeter. Gardeners in areas that do not experience hard frosts can grow mustard greens throughout the year.

Mustard greens grow well with full sunlight, although they will also tolerate partial shade. The Cornell University Cooperative Extension says this shade can help with growth during warmer days.

The soil should be well-drained and fertile, amended with organic material such as compost. While mustard greens can tolerate slightly alkaline soil, they grow best in soil with a pH level of 6 to 7.5.

When growing in the spring, seeds should be started indoors four to six weeks before the last expected spring frost. Direct sowing can take place early in the season, as seeds will germinate in temperatures as low as 40 degrees. You can also plant seeds every couple of weeks to allow for successive harvests throughout the year.

In colder environments, a hoop house can be beneficial for growing mustard greens later in the season. When covered in plastic or row cover, this arrangement will protect the plants from hard freezes.

Seeds should be planted at a depth of one-quarter to one-half inch. Allow one inch of space between the seeds.

Mustard greens will grow quickly, but need plenty of water. Bonnie Plants says you'll notice that the plant will start to wilt if it is not receiving enough moisture. Applying one inch of water in one watering will help meet the plant's needs during dry periods and develop a stronger root system.

Once seedlings start to develop, thin them out to allow more space between them. The Cornell University Cooperative Extension says there should be six inches between seedlings, although larger varieties may need as much as 18 inches of room. The thinnings can be eaten with salad.

Fertilizer can be beneficial in supporting lush leaf growth. A nitrogen-based fertilizer should be applied once a week if you plan to harvest often. Otherwise, a treatment every two weeks is sufficient.

Be careful when removing weeds around the mustard greens. The plant has a shallow root system, so it is easy to damage the roots if you dig too deep.

Mustard greens are susceptible to certain pests, including aphids, flea beetles, cabbageworms, and slugs. The Utah State University Cooperative Extension says row covers can help protect against insects, and that a spray of water is often enough to dislodge aphids. Other pests can be controlled through insecticides or insecticidal soaps.

Since the plant is a member of the cabbage family, it can be affected by the disease clubroot. However, it is easy to avoid this disease if you are careful about where you plant. Bonnie Plants says you shouldn't plant mustard greens in an area where other members of the cabbage family have grown in the past three years.

The leaves of mustard greens should be harvested when they reach full size, and before the seed stalk forms. Cut the leaves about two inches above the soil. One option is to only harvest the outer leaves, allowing the central leaves to continue growing.

You can also cut all of the leaves at once, leaving a central stub which will continue to produce leaves. This method gives you a greater range of tastes, since younger leaves typically have a milder flavor.

In spring plantings, mustard greens will eventually start to produce yellow flowers during hot summer days. At this point, you can taste a leaf to see if the quality is still good. If not, the crop should be pulled up and composted. However, you can save the flowers for an indoor display.