February FAQ with Melinda Myers

Horticulturalist Melinda Myers answers questions you might have wondered about.

I am growing red raspberries for the first time. I  have received conflicting advice on when and how to prune. can you please help?

The type of raspberry determines what and when you prune. Summer-bearing raspberries produce fruit on two year old canes. Cut the bearing canes back to the ground after the summer harvest. In late winter, thin the planting to 4 to 6 canes per foot of row. Do as little tip pruning as possible, no more than 1/4 the height, to maximize production. Fall bearing, also known as ever-bearing raspberries (pictured) produce fruit in fall from first year growth. These same canes will produce another crop of berries the following summer. Prune out the bearing canes after the summer harvest. Fall or winter pruning can be done on everbearing raspberries. Prune all the canes back to ground level. This eliminates the summer crop but results in a bigger and earlier fall harvest.

I want to start some flowers and vegetables from seed this year. Is it difficult? Which ones should I try?

Long season plants like geraniums and tomatoes require many days to reach flowering and the fruit producing stage. Start these indoors to get a jump on the growing season. Other seeds may be very small or require special treatment so starting seeds indoors is a more reliable option. You will need to provide a warm space, preferably artificial lights, and regular care throughout the spring when starting seeds indoors. Shorter season plants like lettuce and marigolds or those that can tolerate or require outdoor conditions, like a winter chill, can be started directly in the garden. Make a list of your favorite vegetables and flowers. Then check the back of the seed packet for details on when, where, and how to start them. 

I received a pot of spring-flowering bulbs as a gift. Can I plant them in my garden and will they bloom next spring?

Forced bulbs can eventually be moved into your garden. Continue to water, fertilize with a dilute solution of flowering houseplant fertilizer, and grow them in a sunny location until the foliage naturally  yellows and dries. Wait to move actively growing plants outdoors until after the danger fo frost has passed. Once the foliage dies and bulbs go dormant, you can plant them outside as soon as the ground can be cultivated. Some gardeners store the bulbs in a cool, dark location for the summer and plant them while adding other spring flowering bulbs to the landscape. Just remember to plant them when fall rolls around. Once planted, you need to be patient. The bulbs will produce leaves next spring but the flowers usually do not appear until the following year.

My houseplants are infested with whiteflies. Where did they comr from and how can I get rid of them?

Whiteflies often catch a ride into the house or garden on new plants. Fortunately, outdoor plants usually tolerate their feeding and these pests will die during the cold winter. The problem occurs when the white flies move in doors. Their feeding can further weaken already stressed houseplants. Try placing yellow sticky traps in or near the infested plants. Trapping will often reduce the population enough to keep the insect damage to a tolerable level. If the plants are suffering, you may want to use an insecticide. You will need three applications applied five days apart. Start with insecticidal soap or Neem. These are more environmentally friendly chemicals that may provide relief. If not, you may want to try more traditional chemicals like Resmethrin and permethrin. Both are effective against white flies. Make sure you have adequate ventilation when applying these products. And as always, be sure to read and follow all label directions carefully whenever using any traditional or natural chemicals.

There are several black, lumpy growths on the stems of my ornamental plum. Will this kill my tree? How can I keep it from spreading to my other plants?

The black growths on the stems are caused by black knot fungal disease. This disease is a common problem on cultivated and native plums and cherries, though all other stone fruit can be effected. Fortunately, it will not attack other types of trees. The stem swellings can girdle (stop flow of water and nutrients) limbs and stunt the plant’s growth. Prune out 6 to 8 inches below and destroy the black and green knots in spring to reduce the risk of new infections. Unfortunately, there may be other disease-infected plants in nearby natural and cultivated landscapes. These serve as sources for future infection for yours and other nearby susceptible plants. There is some work on biological controls so there maybe some good news in the near future. Look for disease resistant varieties whenever possible.