Winter Tasks

As we move into winter, we are presented with a new set of gardening tasks as well as some opportunities. It's also the time of year when rainfall amounts and temperature are key factors to consider when caring for your trees and shrubs. This is when your trees will undergo change and you should think about harvesting your citrus.

Trees

If winter rains are abundant, established desert-adapted trees do not need supplemental watering this month. Otherwise, water once deeply during the month. For non-desert trees, water deeply once this month. Continue to water newly planted trees every two to three weeks depending on the temperatures. Watering mature trees now, even native trees, keeps them vigorous through the warm season to come. It is considered by some horticulturists to be the most important watering that trees will receive. Long slow soaks in the region around the tree are best while being sure that you water to a depth of at least three feet. This month, do not prune frost-sensitive, evergreens, or leguminous trees like mesquite, ironwood, acacias and palo verdes. Mesquites begin to lose their leaves this month as they fade to yellow or brown and begin to fall off which is normal leaf loss in these plants. While screwbean mesquite is completely deciduous each year, velvet mesquite lose their leaves gradually, often as the new leaves emerge.

Shrubs

Continue planting cold-hardy shrubs. Cold-hardy deciduous shrubs should be planted before they leaf out. Be prepared to protect tender shrubs like red bird of paradise and yellowbells. On cold nights, throw a sheet, blanket, or frost cloth over the plant to provide temporary protection. Water shrubs every three to four weeks depending on the temperatures but do not fertilize or prune this month. Wait to clear out any frost damage until all danger of frost is past.

Harvesting Citrus

The best place to keep most citrus is on the tree as long as possible. Citrus will grow sweeter on the tree even after ripening. Tangerines will not stay on the tree as long as other citrus. Once you pick oranges store them in a sturdy open carton or box in as cool a place as possible. Citrus stored this way should keep for 10 days to three weeks. Lemons keep best in the refrigerator where they will remain fresh for about six weeks. Citrus can be frozen in sections with the membrane removed and packed in its own juice. If you want to keep it for more than six months, add teaspoon powdered ascorbic acid to each quart of juice used to cover the sections. Orange, grapefruit or lemon juice can be frozen in glass containers to prevent "off flavors". Orange juice may separate after thawing because of enzyme action. There is no way to prevent the juices from separating but it does not affect the safety or flavor.

Cacti

If your saguaro or other cacti have a reddish color during the winter, it may simply be a response to the cool dry conditions of winter and nothing needs to be done.

Bougainvillea

If you would like to take some of those magnificent Bougainvillea flowers inside the house to enjoy, the trick is to immerse the bracts (floral part) in water for one hour before placing them in a vase.

Pre-emergent Herbicides

As rainfall here occurs primarily in the winter and early spring months, it is appropriate to apply pre-emergent weed control to prevent germination. Water it in to a depth of one inch to activate it but do not cultivate the soil. Once these products are watered in, they are safe around pets and children. Pre-emergent herbicides will control grasses and broadleafs, making gardening easier. And remember, don't apply pre-emergent herbicides anywhere you will be growing plants from seed.

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Valentines Day

February brings us Valentine's Day and, perhaps, thoughts of roses. As it happens, February is a good month to pay attention to the roses in your garden as well as general fertilizer, pruning and watering needs.

Roses

Bare root roses should be planted by mid-month while container grown roses can be planted until early spring. Check and be sure that they have been in the container long enough for new roots to have been formed and were not simply bare root roses moved to a container recently. Established roses can be fertilized around mid-month which is weeks before a target bloom date of April 1. Some gardeners wait until the first growth has reached 2 inches in length before applying fertilizer. Any necessary pruning should be finished by mid-month.

Fertilizer

Some general rules/guidelines for fertilizers: -The three numbers on fertilizer packages refer to the percent of nitrogen, phosphorous, and potassium in the product. -Only apply fertilizers when plants are actively growing or it will be washed away before they can use it. -Don't fertilize frost-tender plants until danger of frost is over, usually early to mid-March. - Apply fertilizers carefully. Too much fertilizer can cause salt burn and too little can cause nutrient deficiency problems. -Water both the day before and immediately after applying granular fertilizers to reduce the chance of salt burn. Fertilize deciduous fruit trees with nitrogen when they leaf out. Mature citrus should be fertilized 2-3 times per year, in February, May and July with 1/3 to of actual nitrogen per feeding.

Pruning/Watering

Finish pruning non-native deciduous shade trees, deciduous fruit trees and grapes by mid-month. Prune frost sensitive citrus after they begin to leaf out, if needed. As a general rule, citrus needs to be pruned only if there are aberrant branches ruining the shape of the tree. Continue to water citrus and landscape plants deeply once every 3 to 4 weeks unless rain is adequate (which it hasn't been) to provide freeze protection. Did you know that Native peoples planted by the signs of nature? When mesquite trees began to leaf out in late February/early March, it was time to plant crops. So, prepare your garden soil for spring planting. Trees, shrubs, groundcovers, and native plants can develop root systems before the heat hits.

Pests

Aphids- These are cool season insects found on the growing tips of many annual plants and shrubs where they suck the sap. Hose aphids off or spray them with soapy water. Add 1 teaspoon to 1 Tablespoon of non concentrated dish detergent (don't use citrus-based soaps) to 1 gallon of water. Before spraying the entire plant, test a few leaves for leaf burn.

Rabbits- Are they eating up your plants? Some plants to avoid are British ruellia, dwarf ruellia, bush morning glory, hearts and flowers and ice plant. They are both tasty and a good source of water which is what the rabbits are after. However, there are some plants that they don't find very appealing. These are bur-sage, chapparal sage, golden fleece daisy, creosote bush, euphorbia rigida (gopher plant), rosemary, and turpentine bush. You can protect ornamental plants that are appealing to rabbits with chicken wire for the first year after transplanting. Maintain a schedule of deep, infrequent watering and once they are established, rabbits feeding on them should not be a problem.

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Time For Planting

The month of March is a great month for gardening in the desert. With many hundreds of plant varieties available at nurseries this month, it would be wise to ask some questions before deciding on your purchases, the first set related to where to plant.
-What will its mature height and spread be?
-Does the proposed planting site allow it to reach maturity without interfering with roof lines, sidewalks and entryways? Remember, regularly cutting back a plant because it outgrows its space is usually detrimental to the long term health of the plant.
-What are the light exposure requirements?
-Does the plant need full sun, partial shade or shade during the hot summer afternoons?
-Don't choose sun-dwelling natives for a shady southern exposure or plant a large leafed shade dweller against a western wall.

Knowing what your plant requires will help you pick varieties that will thrive in your landscape and make it less likely that they will have to be replaced. In deciding what to plant, you should consider the following.
Cactus- Plant all types of cacti and succulents. Propagate from existing plants with cuttings or offshoots. Allow cactus cuts to dry and callous over two to three weeks before planting. However, plant agave, yucca and aloe cuttings immediately.
Herbs- How about an herb garden to perk up your cooking? Try favorites such as basil, chives, marjoram, mint, oregano, parsley and sage which all grow well in desert herb gardens.
Annual Flowers - As winter-growing annuals begin to decline at the end of the month, remove them. It is indeed hard to be ruthless when there are still a few flowers or a bit of green. To fill the gap, replace them with warm-season annuals. Unless you are saving seed, keep replacing spent annuals weekly to keep the garden looking sharp and tidy. Consider flowers that attract butterflies such as bee balm, cosmos, Mexican sunflower, sage, sunflower, verbena, yarrow, and zinnia.
Remember to rotate plantings of vegetables and flowers each season to different areas of the garden. This practice of "crop rotation" prevents plant specific pests and disease from building up in the soil.

March Tasks

Some additional garden tasks to consider this month include the following.
-If you've planted tomatoes, put shade cloth high over them to ward off leaf hoppers (small, wedge-shaped leaping insects), spreaders of curly top virus. Also, clean straw placed under plants helps keep tomatoes off the ground.
-Continue fertilizing established roses on a 6-week cycle. Apply 1/4 to cup of Epsom salts. Use amendments such as sulfur or peat moss to reduce soil alkalinity to a pH of 6.5 to 6.8 which is the pH that roses prefer.
-Maintain deep, regular watering on established cool season annuals as they finish out their life span. This is particularly important if you are saving seed from the plants.
-Mulch heavily under plants and on paths. Mulch conserves water, cools soil temperatures and reduces weeds, or at least it makes them easier to pull. Compost, grass clippings, leaves and straw can be used. Materials that decompose more slowly such as pine needles, wood chips, and sawdust are best suited on paths.

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