Question: We had a nice size crop of Concord grapes this past summer. The grapes were still a bit small compared to what I’m used to. They are more sweet than tart but I’m not sure how long to leave them on the vine. Any thoughts?
Answer: Grapes no longer develop sugar once they’re picked. Other examples of fruit that don’t ripen after picking are cherries and figs. Leave them on the vine as long as you can.
Some fruits like peaches and plums continue to develop sugars and become sweeter after they have been harvested. When you pick grapes, figs and cherries what you pick is what you get.
Bunches of grapes as well as the berries themselves ripen at different times. Usually a good time to harvest is when there is a small percentage of the berries that are overripe and beginning to shrivel.
Don’t harvest grapes all at once. Harvest bunches which are ripe and delay harvesting those that are not quite ready. You may harvest two to three times a week depending on how hot it is.
The hotter it is, the faster they ripen. As grapes ripen, sugar content increases about 1 percent every two to three days. The best indicator is to taste them. If they taste good, they are ready to pick.
Next year, remove smaller bunches so remaining bunches are spaced about every 10 to 12 inches. Remove very small bunches entirely. Cut about one third off of the bottom of the remaining bunches. Do this when the berries are about the size of small peas.
As long as the vines are getting plenty of water during fruit development and they’re thinned, you will get larger berries and bunches.
Question: I have two 20-year-old African sumacs in my back yard that drop nearly all their leaves every summer. Every fall they always come back. Is this normal? Beautiful tress but they make a real mess!
Answer: African sumac is a messy tree. There’s going to be a lot of leaf drop and the female trees will drop a lot of berries. The seeds in the berries germinate easily and you may see seedlings popping up all over.
Sparrows and mockingbirds love the fruit from the female tree and help to disperse new seedlings all over your neighbor’s landscape. The male trees produce pollen that is pretty allergenic usually around February or March. These are drawbacks to African sumac.
Question:
Answer: The green bush daisy or Euryops should bloom all through summer and stay dark green if the soil was amended with compost when it was planted and fertilizers are applied regularly.
If you put this plant in a rock landscape with little soil improvement or have it surrounded in rock mulch yellowing is quite common. It will do much better with improved soils and an organic surface mulch such as wood mulch.
For it to continue to flower through the summer, the soil should remain moist and not dry out. They don’t like rock mulch if this is what you have.
Try adding iron and good quality fertilizer such as Miracle Gro or Peters applied to the soil and watered in about once a month. An addition of compost around the plant and watered in will help as well.
Question:
Answer: I hesitate because I don’t know what you’re going to find in apricot trees locally this time of year. Selection of apricots is limited in Las Vegas with maybe a dozen or so varieties. You might have to order online if they even have left or wait until spring.
One of my favorite apricots that stays about 6- to 7-feet tall and requires little additional pruning when trained early in its development is gold kist apricot grafted on to nemaguard rootstock. This is a normal size apricot tree. The fruit is excellent.
Question: We planted an African sumac tree three years ago that is showing a lot of new green leaves now. Could you please let me know how much water it needs? It was deep fertilized at the beginning of spring.
Answer: Are you sure you aren’t seeing flowers? These trees flower in late fall and into the winter months in the northern hemisphere.
Trees require more water as they get older and larger. At 3 they require more water than when first planted. I would normally add another emitter now to give it the extra water it needs.
As it grows for another three or four years it will require more water than it needs now. You should add another emitter then to deliver more water. You should avoid increasing the minutes.
I estimate that after three years in the ground your tree should receive about 10 to 15 gallons each time you water if planted from a 15-gallon container. I can’t give you the estimate in minutes because I don’t know how much water the plant is getting in one of its minutes.
You should determine how much water is being delivered to the tree. I’m don’t know if you’re using a drip system but emitters usually state the number of gallons per hour that it’s delivering or they are color-coded.
Add all these gallons together and divide by the fraction of the hour you are watering. For example, if water for 15 minutes you would divide by 4, 30 minutes divide by two. Do not water landscape trees and shrubs daily. This time of year once a week should be adequate.
You can fertilize the tree yourself. Place some fertilizer underneath each emitter or use fertilizer stakes such as Jobes next to each emitter.
If you are watering in a basin around the tree, sprinkle fertilizer in the basin and water it in and save yourself some money. Don’t put fertilize closer than a foot from the trunk.
Question:
Answer: This insect can survive in Southern Nevada through the winter in the soil. If these are potted plants you can replace the soil but cultivating the soil several days before planting will help to expose the bugs to birds.
I would watch for this problem in the future. These insects have wings in their adult form so they will fly into your flower bed from the neighbor’s yeard. The two things to look for are the holes in the leaves and those little black specks which is budworm poop.
Next year in May or June start looking for that on your petunias and other susceptible flowers. I would not give up on petunias and nicotiana just because of budworm. Put down a couple of protective sprays of Bt, spinosad or any synthetic pyrethrin spray in April and May.
Robert Morris is an area horticulture specialist and professor emeritus in horticulture with the University of Nevada Cooperative Extension. Email questions to
morrisr@unce.unr.edu.
