Once again, vegetables seemed to be on gardeners’ minds as well as an unusual insect living in the ground.
Q: What are the large wasps flying in and out of a hole in our yard?
A: They’re most likely cicada killers. They live in holes found in yards. As the name implies, the cicada killers capture cicadas and feed them to their young, so they’re good insects.
They are flashy, heavy-bodied brown-and-yellow wasps an inch and a half long. Expect to see large numbers flying low to the ground, but stinging incidents are rare.
Q: Why won’t my tomatoes turn red on the vine? They are remaining orange.
A: It is because of the heat. Tomatoes like temperatures below 90 degrees and it affects the ripening mechanism.
Once they get to the orange stage they are ready to harvest as they ripen from the inside out, so finish reddening them on your kitchen counter if that’s what you want.
Q: Can I control the spreading of squash, as they are consuming my yard?
A: Yes! Pinch out 4 to 5 inches of soft growth at the ends of your strong runners.
This causes side shoots to develop, causing plants to become more compact.
Long runners produce a certain number of flowers, but side shoots produce many more because of the pinching.
Q: We planted some grapevines and are wondering how much to water them?
A: Telling people how to water is very difficult as there are so many variables, but here is a rule of thumb.
Be sure the soil is moist at least 12 inches below the surface.
To check this, the next day after watering, push a piece of rebar or something similar into the earth.
Where it stops is how deep the water penetrated. Adjust your drip system to accommodate the grapes so they receive enough water.
Remember, grapes are not big water users. If you have vines running all over the yard, you are watering too much.
Q: How do we tell when to shade our vegetables?
A: The plants will tell you. The first telling signs are bleached out or yellow patches on leaves on the southwest side of the plant.
This varies, but usually when temperatures rise above 90 degrees we need to consider shading vegetables.
Tomatoes scald quickly if left in direct sunlight. Fifty percent or higher shade cloth is widely available and works well.
Summer squash, melons and cucumbers need full-morning sun to encourage pollination and to ripen the fruit. Expect bees busy working your vine crops early in the mornings.
Q: What is Bt you recommended in your June 2 column?
A: Bt stands for Bacillus thuringiensis and is a bacterial pathogen of insects. When eaten by susceptible insects such as the tomato hornworm, tomato fruit worm, cabbage loopers, grape leaf skeletonizers and other caterpillar type insects, it plugs up their digestive track and they soon die. Nurseries sell Bt as Thuricide.
Q: I planted asparagus two yeas ago and the ferns are becoming very distracting. Can I cut the top growth back to the ground now?
A: No! The foliage is building up reserves for a bountiful crop next spring.
Do your cutting in November and cover the area with mulch to keep the soil moist around the crowns.
Consider the ferns tropical plants in the meantime.
Keep weeds under control as they rob the asparagus from developing more. You’ll see spears emerging in late January. When production slows five to six weeks later, let the ferns begin the replenishing cycle.
Q: My ocotillo hasn’t leafed out for three years and didn’t flower this year. Is it dead or alive?
A: Cactus expert David Turner said to mist ocotillos every evening for three weeks and if it doesn’t leaf out it is most likely dead.
I tell people to bend the rods. If they bend they’re alive and if they break they’re dead so remove those rods.
Q: Why are my plants turning yellow? I water them every day.
A: Overwatering is the big reason for yellowing.
The excess moisture around the roots depletes the oxygen necessary to take up nitrogen.
After you’ve adjusted the watering schedule, give your plants a shot of fertilizer, but wait to see if the plants green up on their own, first.
Linn Mills writes a garden column each Sunday. You can reach him at email@example.com or call him at 702-526-1495.