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.

We planted 2 linden trees about 5 years ago. They are doing very well, but one of them has suckers that grow every year. By July, they are about 2 feet tall and this is when I have been cutting them off. Is this OK? Is there a better way to handle this? Can the suckers be prevented from growing? Why does one tree have them and not the other?

Occasionally trees may send up sucker growth from mature tissues originating at or below ground level. The best way to prevent recurrence of this is to trim back the suckers as close to the point of origin as possible. Sometimes this may require careful removal of some soil to expose the base of the suckers. Remove the growth by cutting as close to the mature tissue (from which the sucker emerges) as possible, or by twisting and pulling the shoots if they are young and tender. The latter usually provides better control because the latent bud that is causing the sucker is often removed in the process. Once removal is completed, replace and firm the soil.

In some cases, all that can be done is to continue the pruning ritual since no treatment is really available to prevent these suckers from growing. Eventually, some trees will just stop on their own, while others will go on for years…that’s just how nature works.