I have a Lonicera ‘Dropmore Scarlet’ vine that gets about 4 hours of sun a day. I noticed that the top of the plant was covered with masses of tiny, white insects. Starting at the bottom of the plant, the leaves had all browned and fallen off. What is the insect and what should I do?

The insects on the new growth and the brown leaves at the bottom may not be related cause and effects. The insects you are observing on the new growth are no doubt aphids. Aphids love honeysuckle and are often found on the new growth causing malformed, rolled up foliage and twisted stem growth. Since they tend to cluster on the tips (and have distorted the new growth anyway), trimming them off is often an effective control strategy. Introducing lady bugs as a natural predator also works. Chemically, a systemic insecticide such as Orthene does a good job, even though the rolled up leaves may protect them from direct spraying.

The brown leaves at the bottom are due to something else. It could be due to insufficient sunlight (honeysuckles do best in full sun) or lack of fertilizer (a balanced 10-10-10 will normally do the trick). If you noticed the leaves with a dusty, white coating before they turned brown, the cause may have been powdery mildew. Honeysuckles, particularly those in shaded locations, are quite susceptible. “Remedy,” a new fungicide from Bonide is quite effective in the control of mildew. It is safer to use and not as harmful to the environment as many of the other fungicides.

What is meant by the term “tissue culture”?

In its simplest form, tissue culture (also known as micropropagation) is a technique of plant propagation whereby plants are started from very small pieces under aseptic (sterile) conditions usually on an agar-based medium. Plant parts as small as tiny stem tips, nodes, embryos, seeds or pollen are placed on a special culture medium. The nutrient medium used may vary considerably depending on the growth requirements of the specific plant grown. By varying the medium content, the plant part may be caused to produce undifferentiated callus tissue (which may be further subdivided later on), multiply the number of plantlets produced, grow roots or multiply embryos.

Tissue growing techniques allow gardeners to propagate large numbers of specific clones in a relatively short time in a small amount of space. These techniques can also be useful in producing pathogen-free plants. Tissue culture techniques are widely used by orchid growers and other members of the greenhouse and nursery industry.