Ice water after harvest removes insects

A: I realize these bugs look a little disgusting, as their name suggests. Spittle bugs are not really a terribly bad bug and can be removed easily from the rosemary by immersing it in cold water after you harvest it. You would do the same if you are harvesting other herbs.

Take some very cold water, preferably with some ice in it, and plunge your cuttings into this cold water. If you let them soak for a fairly short period of time the insects will dislodge from the plant and float away from it. You should be able to wash any spittle from the plant itself with a strong stream of water.

Q: I seem to have trouble every year growing zucchini. I never get any zucchini or they start to develop and then shrivel up. The leaves turn a very light green and are almost yellow. I sent you some photos. New growth starts nice and green but then turns pale. They are on a drip system; they get 1 gallon every two days. They are mulched at the base and receive sunlight about 80 percent of the day. I would appreciate any suggestions you or your staff might have.

A: From your photos, it seems your plants are pale green at best and perhaps a little yellow. I would suggest that you fertilize a bit more often and make sure that you are planting into fertile ground.

I like to see a good preplant fertilizer high in phosphorus at the time of planting. After about two to three weeks, you would go ahead and apply a high nitrogen fertilizer to get some vigorous growth and a healthy plant. Once fruit begins to set, you could go ahead and side dress, or apply small amounts of fertilizer high in nitrogen about every three to four weeks as the season progresses.

Now getting back to your zucchinis, it appears to be a lack of pollination; the fruit is beginning to set but has not been pollinated so the fruit shrivels and dies. Normally, if you have enough pollinators present, such as bees, then you should have normal fruit set.

By now I would be assuming that your plants are steadily producing and you’re up to your eyebrows in zucchinis. Watch for pollinators and make sure they are visiting your garden.

Q: I just installed an in-ground fertilizer system that uses liquid or powder fertilizers. It works through my irrigation system. My problem is which fertilizer to use. The sales people I’ve encountered don’t have a lot of experience with in-ground systems. Can you give me some guidance?

A: Each type of fertilizer has a different impact on plant growth. The first number, nitrogen, encourages leaf and stem growth and a dark green color. The middle number, phosphorus, encourages root, flower, fruit, seed and oil production. The last number, potassium, is more difficult to identify in its importance for plant growth, but generally speaking it is important in helping to reduce plant stresses from things such as heat, cold, drought and the like.

It is difficult to just give a blanket recommendation for a fertilizer for everything in the yard. However, you are usually safer if you reduce the phosphorus level and just have higher levels of nitrogen and potassium. This is because phosphorus can accumulate in soils unlike nitrogen and potassium, which can move more readily with water.

This will mean that you will have to add a phosphorus fertilizer to those plants, separately from the others, which bloom or produce fruit. Also when putting new plants into the yard or starting plants from seed you should still add a starter fertilizer initially. Starter fertilizers will be high in phosphorus. Keep in mind that when using fertilizers high in nitrogen, those above 20 percent nitrogen, keep the application levels very low but frequent.

Q: I worked hard to make my artichokes flower. I have given them vitamins to grow flowers and vitamins for the leaves since the leaves were quick to turn yellow in the past. With our temperatures now in the triple digits, I have been watering once early in the morning and once late in the afternoon. About four days ago I noticed that my artichoke plants had flowers with black spots all over them. I don’t know what’s causing this. I enclosed photos (which newsletter subscribers can see).

I am also having trouble with flowers on my hibiscus, Rose of Sharon. Some of the buds are tight and deformed.

A: I am thinking you have Western flower thrips on your flowers.

Thrips are tiny insects that feed on plants with a rasping mouth part and then suck out the contents of the damaged plant tissue. As their name suggests, Western flower thrips attack flowers resulting in flowers that are deformed, plant parts that are deformed and fruit that may be severely scarred. Sometimes flower buds will abort. If these thrips feed on young developing flowers, the flowers may never develop.

Western flower thrips feed on many different plants including roses, gardenias, chrysanthemums, impatiens, marigolds, hibiscus, verbena, petunias, nectarines and plums among others. Sometimes their feeding can leave the leaves with a silvery appearance and you should see the presence of black specks, which is their fecal matter.

Thrips are difficult to control but a relatively new product, containing an active ingredient called Spinosad, has shown very good control of Western flower thrips.

Q: About three or four years ago I grew cucumbers by the armful. The last couple of years I’ve had no luck. I put the seeds directly into the ground, seedlings come up, the true leaves develop, I get some beautiful plants with flowers and then overnight the plant wilts and dies. I can’t see any bugs. I water every day with microsprinklers for about 10 minutes. Skipping water one day lets the soil dry out too much here in Las Vegas; I tried it. I sure would appreciate any help and suggestions.

A: This very well could be one of the soil-borne diseases such as Verticillium or Fusarium. It is important to rotate vegetables and not plant them in the same spot year after year. Soil-borne diseases can build up in intensity if continually cropped with vegetables in the same family year after year.

You could plant corn or leafy greens in that spot in following years and then come back to it in a couple of years. Also pick seeds that have V or F after their name. These are varieties that have been bred to be resistant to these diseases.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at morrisr@unce.unr.edu.