Q. I put up some shade cloth to protect my fig trees from the heat. The new growth is good and the leaves look fine so I don’t think its water, but I think they can’t handle this heat. I will take the shade cloth down after the temperatures come back down to maybe 100F. A. I have grown 15 different varieties of figs over a period of 20 years and none of them needed shade cloth. They were all in full sun. They did however have lots of wood mulch covering the soil and regular irrigations applied when they were producing fruit.             The usual problem with fig fruit drying up in the heat is a lack of available water in the soil. For several reasons this problem can be resolved simply through soil improvement. Figs are an “oasis” plant, similar to palms, and the organic content of the soil near sources of water is higher. Figs in those locations have access to more water and better soils.             If you’re going to use shade cloth, never go higher than 30 – 40 %. When using shade cloth, achieve a balance between food production and food quality. In the case of figs, the fruit needs protection from birds rather than the sun.

 Learn the positives and negatives of artificial grass installed in the desert in this episode of Desert Horticulture.

Q. We moved to Las Vegas four years ago and had a professional landscape our backyard. We now have eight magnolias as well peach trees throughout our backyard surrounded by large rock up against the trunks. This rock makes it difficult to fertilize the trees and pick the fruit. Our gardener told us the trees are not getting enough water. Should I pull the rocks away from the trunk of these trees and put wood mulch around their trunks?     A. First off, both peach trees and magnolias will not like the rock laid on the surface of the soil and surrounding the trees. You will see them start to suffer from this practice in three to five years. Both prefer an “organic” mulch that can decompose into the soil and improve it. That means a four-inch-deep layer of woodchips.             When buying peach trees, they should be on a semi-dwarfing rootstock such as Citation. If bought on this dwarfing rootstock, they can be planted about ten feet apart, pruned to keep them small, the soil enriched with a good quality compost at planting time and the soil covered with four inches of woodchips, not rock. So yes, pull the rock back about three feet from the trunk and lay down four inches of woodchips instead. Young magnolia planted in fescue lawn in Las Vegas.             Magnolias? Eight of them? Wow. I’m assuming you are talking about southern magnolia with its beautiful flowers. Even in Georgia, where they belong, one specimen tree is more than enough for a large yard. Magnolias growing in Georgia can get 75 feet tall with a similar spread! These trees are NOT meant for backyard, or front yard, landscapes (desert or no desert) unless you have a huge property and water is cheap.             As these trees get older (if they do) they will become a nightmare to maintain and water. Get rid of them now before they get fully established. One tree is enough to satisfy your curiosity and you will probably remove it in less than ten years anyway.             Let’s say you keep the rocks. Using large rocks around plants has both pluses and minuses. If they are large enough, fertilizer or compost can be flushed on to the surface of the soil by washing it through the rock with a stream of water from a hose. Large rocks are also great for keeping people out. But you are right. Large rock makes it difficult to harvest and prune fruit trees. In my opinion, rock larger than 3/8-inch diameter is difficult for walking safely.

Q. I have been looking for seeds for planting fall vegetables and herbs and not having much luck here in Vegas. Where should I start?  A. Start with varieties that have done well here in the past. Dr. Wittwer’s Moapa Valley vegetable growing “Bible” is a good place to start. He mentions several older varieties that have performed well for him. I can forward a copy to you if you don’t have it.             Slowly introduce new varieties that have no production history in the desert. Be careful. Not all varieties produce well in a desert climate. Consult online vegetable seed sources like Gurneys, Park Seed Company, Territorial Seed Company, Baker Creek Seed and Grow Organic. Specialty seed sources like Kitazawa Seed and Seeds from Italy provide some interesting and heirloom seed sources.             Heirlooms don’t produce as much food as hybrids, but they are oftentimes “tastier” if you can get them to produce here. heirlooms are not as “finicky” as hybrids so they don’t require as much fertilizer and care.

Q. We have four established Raywood ash trees on our small cul-de-sac. Three are doing fine but the one directly in front of my condo is not. Just over the last few weeks, several brown dying  branches have appeared. Our landscaper said all that needed to be done was to trim the branches and give it more water. What’s your thoughts? A. Large dying branches in ash trees may be from a disease called ash decline. It can be from a lack of water but if the tree doesn’t look much better after three weeks when larger amounts of water are applied, then it is probably ash decline disease. There is no cure for ash decline and the tree should be replaced with a tree that is NOT an ash tree.   Ash decline disease or drought. Water the area under the tree with a sprinkler for an hour once a week for three weeks and find out.             Plant diseases don’t happen all at once just like they don’t happen all at once with diseases in humans or animals. The reason you see it on one tree is because it may be just beginning. Eventually if one tree has it, they will all get it whether that is in 10 years or 15 years, I don’t know. Keep an eye on the others. Remove infected trees early.

Q. Does Ironite help Italian cypress if they are turning brown? A. No. Ironite may help if the problem is an iron deficiency or the plants can’t take up enough iron. Iron problems on plants turn yellow first before they turn brown and die. If the cause of the browning was from poor irrigation management and the soil staying too wet because of poor drainage, then Ironite will not do any good. The same is true for browning due to spider mites.             By the way, Ironite only works if the soil is not too alkaline (pH above 7.6). Most of our desert soils are closer to 8.0 or higher. Mixing in lots of compost and adding water helps lower the soil pH close to the mid 7’s. But if the soil has been covered in rock for a few years then soil pH (alkalinity) will be close to 8 or above.

Q. I have grubs in sections of my fescue lawn. They have been a problem in the past and they are again this summer. How do you prevent grubs from re-infesting a lawn each summer? Grubs feeding and growing larger in the soil beneath a lawn. They will become “June bugs” in the summer. A. Make sure the brown areas you see is damage due to grubs before you apply grub control products. Most brown spots on lawns during summer months are irrigation or disease related, not from grubs. Usually grub damage starts appearing early in the summer.             Brown spots resulting from grub damage is probably the easiest to determine. In early summer, grab a handful of grass from the edge of a suspicious brown spot and lightly pull. If green grass is pulled up without roots on it, then your lawn probably has grubs. YouTube videos will show infested grass rolling back “like a carpet” but that’s only on sod forming grasses like Kentucky bluegrass. We have mostly tall fescue in our lawns which is a “bunch grass”. That makes identifying grub damage in our lawns different. White grub larva just before it will become a “June beetle”.             If you are convinced that brown spots are due to grubs, then apply an insecticide for grub control to lawns in late spring. If you want to get a jump on controlling white grubs, apply the same insecticide to the lawn September through October.

Mulch is anything laid on the surface of the soil. Selecting the right mulch and using it can mean plant success or failure in the long run. Organic and inorganic mulch play different roles in landscapes. Rock mulch may or may not be the right thing to do with your landscape. Learn why on this episode of Desert Horticulture.

 I am helping an employer find a part time vegetable and herb gardener in the downtown Las Vegas area. Flexible schedule, time and hours. Easy parking. Good with the public.  Contact me if you want more information.  [email protected] 

Q. This summer I had a terrific garden with lots of tomatoes, but my zucchini died by mid-summer, green beans were lush and beautiful but produced nothing, and just a couple of fruit from my cantaloupe but no watermelon. I’m not sure if the roots of my carrots and beets have gotten bigger but they sure have beautiful tops! I rototilled in a bag of manure, waited two weeks, and rototilled again. Be careful when adding bagged steer manure to a garden area. It has not been composted and so is considered “raw”. Let it “rot” in the garden.  A. Several things may have gone wrong for you. In a longer email you said they were planted at the right time of year. I’m not so sure. When it’s hot you should have finished harvesting your beans, carrots, and beets a long time ago. You could be planting for a second crop of these just before cool weather arrives, but you shouldn’t be seeing tops now. These are cool season crops. I don’t know where you got your planting schedule, but I am sending you one that I created for a local company. It’s adjusted for 1000, 2000, and 3000-foot elevations. It also tells you which vegetables you can plant from seed and those from transplants only. You still need to adjust it for your local weather microclimates but it’s correct otherwise. I will be happy to send you a copy by email and to anyone who wants one. Zucchini and melons are warm season vegetables. It sounds like they were planted at the right time. You don’t mention the varieties of vegetables you planted. Maybe you chose the wrong variety. Selecting a good variety for the hot desert and planting cool season vegetables just before cool weather arrives, is a must for successful gardens. I am also sending you a copy of a local vegetable guide that suggests some successful varieties that you can try first. Record what you try and when you plant it. Plant trusted varieties first and experiment with unknown varieties in small numbers. Sounds like you rototilled steer manure into your garden area. Nothing wrong with that. Sounds like the two weeks that you waited before cultivating a second time worked for you. Steer manure is not a bad choice it just depends on where it came from, how it was processed and, taking these into consideration, your level of comfort using it. Make sure you wash all of your vegetables before eating them.