What did we learn from the damage to plants caused by the recent snows?
“Much of the damage could have been eliminated through proper maintenance and care of trees,” said Dennis Swartzell of Horticulture Consultants. Here are some of his observations:
We had more than five inches of heavy snow, which means a lot of water in the snow. This caused snow to stick to branches, resulting in limbs breaking.
The positives: Swartzell found most shrubs and desert plants were unaffected by the snow load.
Turn water off: There is no need to water trees and shrubs for a month and even longer with desert-adapted plants after the kind of moisture we got this past week. “With snow now melting, it is like a slow gentle rain that will soak deep into soil.”
Opportunistic plants: Swartzell finds desert plants will drink all the water you’ll give them, creating unnecessary growth. This means thinning them, which increases the cost of their maintenance. The consultant said to be frugal when watering droughty trees.
Top-heavy growth: Since most of the damage was to desert trees, Swartzell pointed out the need to prune them when we’re going into fall to encourage them into dormancy. For trees such as ash and mulberry, prune them after leaves drop.
Weak crotches: Paloverde and mesquite trees have weak crotches, and with snow hanging on branches, they finally broke.
Swartzell blames weak crotches on how these trees were trained back when they were planted. Ideally, you want limbs coming off the trunk at a 90-degree angle or slightly narrower.
Take a look at your watch; you want limbs coming off the trunk at an angle somewhere between 9 to 10 o’clock or 2 to 3 o’clock. You do not want limbs coming off the trunk between 11 and 1 o’clock; they develop weak crotches and easily break as the limbs become heavier. Eliminate these weak crotches early so you won’t have this dilemma with the next snowfall, said Swartzell.
Overfertilizing: Gardeners overfeed desert plants. This causes a need to do more pruning through the season. “While working at UNLV, I simply cut back fertilizing mesquites and only had to prune them once a year.”
Self-fertilizing plants: Most desert plants produce their own fertilizer. “We call them legumes. You can tell if a plant is a legume, because it produces pods or beans. Down on the roots, legumes produce their own nutrients.”
Tender perennials: Among these are frost-damaged lantana, desert bird of paradise and Tecomas (yellow bells, orange jubilee, etc.). Cut this damaged growth back to the ground. Just in case we get a deep freeze, dump a bucket of mulch over each plant’s crown to keep the frost from totally killing the underground parts.
Don’t prune palms: Commercial gardeners are encouraging homeowners to prune palms now, but it is the wrong time. Fronds hanging down protect the heart of palms from freezing. These gardeners remove all but three fronds, so the palms look like a pencil point with a feather duster on top.
Here is the dilemma with the last snowstorm: Those fronds broke because of the snow load, and left poking up was a spear or new fronds yet to unfold. “If we have a deep freeze, those palms will most likely die,” Swartzell said.
RECYCLE YOUR CHRISTMAS TREE
Make your Christmas even greener by recycling your Christmas tree. The Springs Preserve and partnering organizations want you to help create mulch for local parks and public gardens by recycling your tree. Drop it off through Jan. 15. Go to www.springspreserve.org to find a site near you. Or call (800) 468-5865 to schedule a time to pick up your tree. It does cost $20, and a person vacuums up the dropped needles.
Last year, valley residents recycled more than 18,000 trees, resulting in 200 tons of nutrient-rich mulch. The preserve turned this mulch into humus and put it in its vegetable garden.
Before dropping your tree off, remove all lights, ornaments, wires, tinsel and nails.
Linn Mills writes a gardening column each Sunday. You can reach him at firstname.lastname@example.org or call him at 822-7754.