With the onset of very high temperatures, which came on very suddenly due to an abnormally wet and cool beginning to the season, we have seen a number of problems pop up.
1. Warm season lawn transition: This has been a problem for years but is really pronounced this year with the cooler May and early June. Winter or cool season grasses which we over seed our Bermuda grasses with here in order to have a green lawn all winter have “hung on” too long. When the high temps and humidity kick in they finally die leaving no visible signs of the once dormant Bermuda grass in sight. Bermuda gasses can only store up enough energy to remain dormant for so long (late April or Early May at the most) when the cool season grass persists longer than that the Bermudas no longer have the ability to rapidly take over and begin to grow back leaving nothing but dead rye grass. Best practice is to force the rye grass out in April or May by lowering mowing heights, thatching, and controlling the amount of water so they “burn up” and in a matter of a few days the Bermudas begin to fill in. Too late? Remove the dead rye grass thatch, fertilize , and keep the soil moist but not too wet and hope that enough of the root system is still present to grow the Bermuda grass back-it usually is! Those of you who have tried to kill a Bermuda grass lawn know how tough it can be so it will probably come back in time. If not you can re sod, plug in pieces of sod, or reseed if your lawn was a common type Bermuda.
2. Sun burned foliage on subtropicals like ficus and citrus: Because we got super hot super quick, plants didn’t have a chance to “harden off” their foliage or acclimate so to speak and most people didn’t have a chance to increase water schedules, especially when temps went above 110 (throw your schedule out and watch plants for necessary water when it gets that high). Here is and example of how much water a “mature” bush needs per watering to thoroughly wet the root zone-a 4′ canopy needs 12 gallons of water/watering. If it is a desert adapted plant it can go a week (under 110) between waterings in the summer. A tree with a canopy of 16′ needs 150 gallons every 7 days. Non desert adapted plants need the same amount but 2x as often. These guidelines can be found at landscape watering by the numbers or come by and pick up the FREE brochure!
3. Agave snout weevil collapse: yes already! normally this is not a problem until August or September. The grub or larvae of the agave snout weevil eats the base, stem, and lower part of the agave plant and unfortunately by the time you see symptoms it is too late. The plant usually collapses seemingly overnight and your left with a pile of putrid smelly plant remains and a bunch of grubs (fishing bait-trying to be positive?). Remove the dead material and pests and use DE or other recommended control for grubs before replanting. If you have agaves you might want to be proactive and use controls now to prevent this.
4. Ficus whitefly: There is a new bug in town! If you live in the Arcadia or Central Phoenix area perhaps you’ve noticed your ficus trees loosing lots of leaves. If so, inspect them and see if you don’t have “dandruff” sized white bugs that fly off the plants when you touch or shake the leaves. Soil drenches of systemic insecticide and fertilizing are the best remedies for this-perhaps someone is trying to tell us something about ficus?
5. Spurge: This weed continues to be a hot weather problem. Spurge produces lots of seed and is spread easily by birds, lawn mowing, ……The best control is to remove or kill the plant(put it in a plastic bag immediately) and get on a regiment of pre emergent control. Dimension seems to be very effective for controlling the emergence of spurge.