Here's what you need to know about growing cool weather annuals

2022-10-09 06:17:01 By : Mr. Wen Dan

Sweet pea, Lathyrus odoratus 'Matucana', is a cool weather annual that produces beautiful, fragrant blooms.

Last week, I mentioned pansies, cyclamen, primula, stocks and sweet peas, but now let's discuss growing them in more detail. 

Pansies are the most popular cool weather annual. They are low-growing plants that produce a large selection of colors, including yellow, white, blue, brown, lavender and orange.

There are two main bloom forms, clear and dark. The dark has a black center in the bloom.

The blooms are available in several sizes that vary from quarter-size to tennis ball-size. If you want a plant with numerous small blooms, violas are available. In addition to single flower colors, the violas and Johnny-jump-up pansy cousins produce a wide range of bicolor blooms. They are especially suitable for hanging baskets and containers.

Grow pansies and their cousins in full sun. They are more sensitive to hot weather than snapdragons and some other cool weather annuals, but they are very tolerant of cold weather. They are available in bloom in nurseries now and will stay in bloom until late spring even if we are subject to serious cold spells.

Cyclamen do best if planted later in October or in November.

Cyclamen, which do best if planted later in October or in November, are the showiest of the winter annuals. They must be grown in the shade in containers or raised beds.

Cyclamen leaves are waxy green, and decorated with silver and dark green etchings. As showy as the leaves are, they are hard to notice in the midst of the blooms. Cyclamen blooms are intense shades of red, white, lavender, purple and pink. Once the weather cools for the season, expect them to stay in bloom every day until mid-April. They are fairly cold-tolerant, but to protect your investment (about $7 per plant) be prepared to cover cyclamen with fabric if the temperature is forecast to drop to 28 degrees or below.

If cyclamen is the showiest cool weather annual, primula is a close second. Primula has a growth habit similar to pansies, and the flowers nearly match the attractiveness of cyclamen.

Grow primula in the shade, just like cyclamen, and protect the plants from cold of 28 degrees or less. In addition, the low-growing primula are a favorite plant for slugs and snails to feed upon. Protect the primula, whether growing in the garden or in containers, with slug and snail bait that is refreshed every two weeks.

READ MORE: Cool weather annuals add more color to San Antonio landscape

Stocks are among my favorite cool weather annuals because of their attractiveness and the fragrance of their blooms. Grow them in the cut-flower garden right next to snapdragons just as soon as transplants become available at the nursery. I tried to grow stocks by seed one time but was not successful. I recommend that you grow stocks but stick to using transplants provided by the pros. Stocks are similar to pansies in that they require cool weather and cool soil to germinate.

Sweet pea is another cool weather annual that produces beautiful, fragrant blooms that decorate the garden and also make excellent cut flowers. That is not to say that it is easy to grow sweet peas in Central Texas, but it is worth the challenge. Purchase a packet of seeds from your favorite nursery, and after you soak the seed in water overnight, plant them in front of a trellis or tall tomato cage in full sun.

The challenge of growing sweet peas is that they don’t respond well to weather that is too cold or too hot. For many gardeners, that has meant that the need to reseed them every month beginning in October and sometimes as late as February until the weather proves suitable for the seeded plants to prosper and bloom.  

Calvin Finch is a retired Texas A&M horticulturist. calvinrfinch@gmail.com