Knowledge of how food is grown may help local chefs

: I am a local producer of herbs, greens and other veggies in Boulder City. What types of garlic did best for you and where did you purchase them? My chefs want lettuce all summer and are quite upset with me because I am having trouble doing just that. Do you know of any lettuces that will tolerate the heat? I have explained to them that lettuce has a hard time germinating in the heat and if it does germinate, it quickly bolts to seed. Why can’t people understand the concept of eating by the season? Can we come and see the University of Nevada Cooperative Extension Master Gardeners Orchard in Las Vegas some time?

A: You can come out any time. The orchard is a public facility and is open Monday through Saturday, but during the summertime, mornings are best. I am nearly always there Tuesdays and Saturday mornings, but it’s hit and miss other days of the week.

Chefs who want local food have to begin to appreciate the seasonality of food. When we try to produce food out of season, we either have to manipulate the environment where the plants are growing, such as using hoophouses or a greenhouse, or accept poorer quality food. This is going to be a dilemma for chefs who just want to substitute local food for the year-round products they are receiving from their suppliers. Most do not understand how food is grown.

You are right; planting most varieties of lettuce now will only cause it to bolt. And in this heat it will most likely be bitter. This is the time of year for local tomatoes, eggplant, cucumbers, squash and the like; food that comes from flowers, not leafy greens.

Many different garlics have done well for us. You can always get California early, the variety in most grocery stores, to do well here if planted in about early to mid-October. That’s a good one to start with. Others that have done well include Red Janice, Polish White, Red Chesnok and Susanville. All have their distinctive flavors and vary in the amount of mouth heat they produce.

Q: I am new to desert gardening, having spent my entire life in the Midwest. One question I have is about the care of oleanders. We planted them in our backyard against the privacy wall. Last year, they bloomed in the spring and then appeared to go dormant with very few blooms the rest of the year. I notice oleanders blooming profusely in other neighborhoods. I was told that we are giving them too much water. They are on a drip system twice a day for three days a week for 15 minutes. Is that too much water for them?

A: Knowing the number of minutes you are watering does not tell me how much water you are giving them. One drip emitter in a drip system can deliver as little water as one-half gallon per minute or as much as 10 gallons per minute depending upon the type of emitter. This is compounded by the number of emitters on each plant.

So, 15 minutes of water could be as little as one-eighth of a gallon or as much as 21/2 gallons multiplied by the number of emitters on each plant. As far as the frequency of application, I would say it’s about right. The frequency of application is how often the water is coming on.

I am not sure why you have the drip irrigation system coming on twice a day unless you are seeing water ponding or accumulating around your plants or running off to another location. The usual reason for having water coming on multiple times in a single day is because the water is not staying put.

In drip irrigation, usually it is applied so slowly it does not run off to some other location. Usually multiple applications in a single day is reserved for spray heads that deliver water in gallons per minute rather than gallons per hour.

If you are frustrated about making the connection between minutes and gallons of water, then I would tell you to run the drip system long enough to get water to penetrate into the soil at least 12 inches deep and preferably 18 inches. You can use a long screwdriver or three-eighths-inch rebar and push it into the soil after you irrigate to determine how deep the water is penetrating. Unless you have water ponding or running off from the drip emitters then I would change it to a single application of water.

Oleander blooms on current season wood. This means that flowers are being created by the plant on stems that are growing this season. Flowers are not created on wood older than this. If you are pruning an oleander in the summer months, you are removing the wood that will create flowers.

Also, if an oleander is growing in too much shade, it will reduce the amount of flowers. Thirdly, if an oleander is very young and growing vigorously, you will see few flowers. I hope this helps.

Q: I have a 10-year-old agave or century plant. While trimming off the lower leaves I discovered an insect hole going into the top of the leaf. There was brownish cocoonlike material on the leaf. When I cut the leaf off, I found a hole about 1 inch in diameter going into the center of the plant. Any idea what kind of creature did this and what should I do to save the plant?

A: This is probably some damage created by the agave weevil, sometimes called sisal weevil. The adult is a black, hard-bodied insect perhaps less than an inch long. It lays eggs in and around agave with the eggs hatching into a white, legless larva with a brown head. I am guessing this happens around April here.

The larva feeds on the crown of the agave causing the plant to appear like it may not be getting enough water and then die, usually around June. When you pick up the agave the base of it is soft and rotten and you can see several of the larvae in the rotten base of the plant.

I am thinking that the holes you are seeing in the agave leaves may be damaged by the adult black weevil feeding. The black weevil has a snout curved downward from its head.

You might want to apply an insecticide for ornamentals to the base of these plants, allowing some of the liquid to run down the leaves toward the crown. However, this time of the year it may be too late. Make sure you read and follow the label of the insecticide and wear protective clothing.

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.