December in the Desert Garden

Prepare for frost now. If you don’t care for your sensitive trees, bushes, flowers, and vegetables before the first frost, it’s probably too late — the first frost will permanently damage them. It is not uncommon to have up to 20 frosty mornings in December, so be prepared to cover frost-tender plants throughout the month.

What To Do in December

Grass

• Your over-seeded winter lawn should be established by now.
• If your winter lawn turns yellowish, fertilize. An application of Ironite will bring back the dark green color.
• Water every 5–7 days, or more often if you notice the soil drying out. Light or sandy soils dry out faster.

Trees & Shrubs

• Wrap the trunks of young citrus and other cold-tender trees with cloth, cardboard, or several layers of newspaper (no plastic) to protect them from frost. Leave them wrapped until the threat of frost has passed.
• Sweet oranges, navels, lemons, tangerines, and tangelos may be picked now, but pick only as needed. As the season wears on, the fruits will continue to sweeten.
• Citrus fruit stores best on the tree.
• Frost-tolerant trees and shrubs may be planted this month. Dig holes three to five times the size of the root ball but no deeper. Set the plant so the top of the root ball is at ground level, then backfill.
• Remove dead branches and water sprouts.

Christmas Trees

• When you purchase your tree, try to get a freshly cut one. Feel the needles for dryness — they should be pliable.
• Cut an inch off the trunk, put it in a stand with a water reservoir, and fill it daily.
• If you buy a living tree, don’t bring it inside until about a week before Christmas, and take it back outside right after the holiday. Once the tree has been outside for a while and is again acclimated to the colder weather, you can plant it or donate it to a school or park.

Flowers

• Flowers can still be planted, so choose your favorite annuals and perennials.
• You can still plant bulbs. Plant them in well-drained soil high in compost or organic matter, with about two inches of sand beneath them. Cover with a coarse material such as peat moss or crushed wood products like bark.
• Chrysanthemums begin to die back after blooming. Cut back dead or dying foliage and add a bit of nitrogen fertilizer.
• Poinsettias will turn yellow if you water them with the foil sleeve still on, because they will sit in the water. Take them to the sink, remove the foil sleeve, water until water comes out the bottom, let them drain for a few minutes, and then put the foil sleeve back on.
• Start getting the new rose catalogs and watch for bare-root roses at nurseries later in December. Get your seed catalogs now, too, and start ordering.

Vegetables

• Plant seeds: beets, broccoli, cabbage, carrots, cauliflower, garlic bulbs, green onions, leeks, lettuce, parsley, peas, radishes, swiss chard, spinach, and turnips.
• Asparagus is best planted in a single row.
• Plant transplants: asparagus, broccoli, cabbage, cauliflower, and lettuce (head & leaf).

Don’t Make These Garden Mistakes in December

1. Don’t pick grapefruit yet — grapefruit are best in late spring.
2. Don’t do any major tree pruning in December.
3. Don’t fertilize trees or shrubs in December. Wait until spring.
4. Don’t over-water.
5. Don’t ignore pest problems.