Weekly Express-News Article

By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist
Saturday, December 22, 2007

“Cyclamen and Primula for Winter Shade”

If you have a flower bed in the shade, consider cyclamen for the winter.  They are the premiere flower for cool weather blooms in San Antonio and South Texas.  The plants are expensive, $5 or more for a blooming plant in a four inch container, but they are worth it.  Red, white, pink, violet and even bicolor blooms are available.  The colors are very intense and seem to glow in the shadiest planting bed.  Cyclamen grows to about eight inches tall and at least that wide.  The foliage is also attractive.  The leaves are leathery with dark and light green patterns.

Place cyclamen in solid color blocks with plants on one foot centers or in various patterns with two colors in the bed.  White and red, pink, or violet are very showy.  Use a raised bed enriched with compost and fertilized with one cup of slow release or winterizer lawn fertilizer per 25 square feet of bed.  In containers, fertilizer every two or three times you water with a dilute soluble fertilizer.  Cyclamen are not xeriscape plants, but they also require good drainage.  Irrigate them whenever the soil dries to one inch.

Deer will eat cyclamen and slugs and snails sometimes cause a little damage, but otherwise pests and diseases are not an issue.  Use slug and snail bait every month; cyclamen do not like hot weather.  If they receive too much sun or when the hot weather arrives near the end of April, they decline.  Cyclamen are generally grown in sheltered beds close to buildings or under trees so it is hard to tell their exact cold tolerance.  They originated in the mountains of the Balkans and have survived the last five winters in my landscape without a leaf kill due to cold.  Last winter one of the freezes did knock off the bloom for two to three weeks.  The best advice is probably to cover them with agricultural fiber or blankets if the forecast is for temperatures less than 28° F.  Such a strategy would probably allow you to have cyclamen blooms every day of the winter.

Primulas are not in the same league as cyclamen as a blooming plant for South Texas, but they are attractive and worth having in containers or beds in the shade.  The vulgaris selection grows low and in the same configuration as a pansy.  The flowers have unbelievable deep intense colors, however.  The colors remind me of crayolas or grease paint.  Reds, blue, purples, yellow, white, and maroons are available.  The foliage is crinkly and Kelly green.

The obconica selection is more upright with pastel colored blooms of white, violet and blue on stalks that rise to 10 or 12 inches tall.  The leaves are a softer green and have a softer texture than vulgaris, but are very attractive.  Slug, snails and pill bugs occasionally feed on cyclamen, but they will run a race to attack primula.  Spread your slug bait immediately after you plant your primulas and replenish it every week if you want the plants to escape any damage.  An alternate slug, snail and pill bug control is to sink plastic cups into the bed with the top at ground level and fill each cup half full of beer.  It does not seem to matter if the beer is flat, stale, expensive or cheap, the pests fall into the cup in great numbers.  The cups placed every five feet do a good job of controlling slugs, snails and pill bugs.