Growing Peppers in Containers in the Desert

Q. I am growing hot peppers in big plastic pots with soil for vegetables I bought from a local nursery. The plants grow fine but the blossoms dry out and fall off without setting any peppers. They get plenty of water, not too much, and the bottom of the pots are drilled out for drainage.

Soil mixes like this Rejuvenate Soil Mix should have quite a bit of compost mixed in it for growing vegetables.

A. Growing plants in pots is difficult in the hot desert. The major problem is overheating of the soil. The side of the container facing the sun can reach 170° F and kill half the roots inside. Losing half the roots of a plant can be quite stressful and cause flower drop. You can kill a lot of roots with a bad soil mix, poor drainage and watering too often, but it doesn’t sound like that’s what’s happening.

Five gallon nursery containers are big enough if you water early in the morning and they are on the east side.

 Make sure the container is large enough. Five-gallon nursery containers are large enough if plants are watered daily, sometimes twice a day when it’s hot, and the soil stays cool. I have had luck with this size container growing vegetables and herbs if on the east side of a building so the container is shaded in the afternoons. Containers may be shaded by other containers or a vegetable bed. But larger, 15-gallon containers work better.

A single cabbage growing in a five gallon nursery container

            Water just before the container gets hot. Moist soil is harder to heat up than drier soil. This is because the water in the soil absorbs heat. I will usually water between 7 and 9 AM.

            Double pot the container. Putting the growing container inside an outer, more decorative container shades the inside container and protects plant roots. This is called “double potting” or “pot-in-pot” container growing. If the containers are the same size and shape, put a layer of pea gravel 2 inches deep in the bottom of the outside container so they don’t lodge.

            Plants grown in the double containers for more than one growing season should be twisted a half turn every month to break off roots growing through the container into the ground.