The University of Arizona
      Maricopa County Cooperative Extension Home Horticulture:
      Environmentally Responsible
      Gardening & Landscaping in the Low Desert

      Timely Tips for April
      in the Low Desert

Don't List
Frequent ?s
Tip of The Month 
Choose native plants or plants which are adapted to our high temperatures and alkaline soils. It will cost you much less time, energy and money it you decide to celebrate the natural beauty of the Sonoran Desert rather than trying to recreate the Pacific Northwest the Southeast or some other environment. Trying to adjust the soil pH, the humidity, the salts in the water, etc. etc. etc. to meet the needs of a maladapted plant is a never ending battle at best. Often the poor plants become stressed and vulnerable to pests & diseases. There are thousands of beautiful plants that thrive here and many that grow no where else. Do yourself and the plants a favor - go native!

Video Demonstration
Ladybird Beetle Demonstration

Ladybird Beetle and other Beneficials : [click here]

Climate Information for April in Phoenix, Arizona

    Average: 0.22 inches
    Record: 3.4 inches (1926)

Temperature (degrees F):

    Average High: 84.5 degrees
    Lowest High: 52 degrees
    Record High: 105 degrees (1989, 1992)

    Average Low: 55.3 degrees
    Highest Low: 77 degrees
    Record Low: 35 degrees (1922)

Note: Rainfall and temperatures vary widely within the valley depending upon elevation and microclimate.

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To Do List . . .
Fruit and Nut Trees

    Plant Citrus Trees - Young two to five year old trees transplant most successfully. Larger, older trees are more costly, harder to transplant without injury (to yourself and the tree), and suffer more from transplant shock. It will generally be three years after transplant before fruit production and that is the same whether you plant a 2 year old tree or a 10 year old tree. Go small!

    Thin deciduous fruit to 6 inch spacing. The earlier this is done after fruit set, the more size response will be expected in fruit remaining on the tree.

    Give special attention to deciduous fruit trees, provide adequate soil moisture for fruit sizing in the late April and May period.

    Apply nitrogen and zinc to pecan trees to produce normal size leaf growth and to enhance kernel development. Pecans also need more water than most other shade trees.


    Frosty winter nipped your herb garden? It is usually safe to prune winter damage from your herb plants anytime after mid-March - perfect now, if you haven't yet taken care of this garden chore. Inspect your Basil, Lemon grass, Peppers, Mexican Tarragon and other frost sensitive plants closely, looking for new growth emerging on the lower half of the plant. Use sharp shears to cut the plant back by 1/3 to 1/2 or more, down to healthy new side shoots. Top dress the plants with new compost and water well for a fresh start.

    Small white balls of frothy foam may show up on the new growth of some of your herbs in spring, especially on Rosemary, Sage and other woody perennial herb plants. These 1/4 - 1/2 inch "balls" are the protective hiding place for the nymph of a relatively harmless insect called a "spittlebug" (Philaenus sp.) which feeds on the plant's sap and uses the foam to hide itself from predators. Spittlebugs are easily rinsed off your plants with your garden hose.

    Often in Spring, we find a Dill or Fennel plant in our garden loaded with aphids and their sticky mess. Aphids usually occur at low levels that are not very harmful to the plant - merely rinse them off with your garden hose and wash your picked herbs well before cooking with them. Insecticides are not generally recommended on herbs, since they are used for cooking. A weaker plant may become heavily infested - either pull and discard the plant, or leave it in your garden as a source of food (aphids) to attract ladybird beetles and other beneficial insects.

Landscape Plants

    As the weather warms and days lengthen, adjust your irrigation timer to water more frequently. Be sure to run your system long enough to wet the top two feet of soil. Deep, infrequent watering is much better than a daily sprinkle.

    Tree water use, desert types being the exception, increases rapidly during this period of leafing out and gradually higher air temperatures.

    Allow your wildflowers to go to seed. They will produce a natural healthy feast for birds as well as reseeding themselves to come up again in your yard next year.

    Make plans for Arbor Day, The Last Friday in April

    Most woodpecker damage occurs during the period of breeding and territory establishment, February through June


    Continue fertilizing established roses, liquid fertilizers can be added at 2 week intervals, follow the directions on the container.


    Begin fertilizing Bermuda grass lawns during late April or early May. Follow the directions on the container.


    Plant Seeds
      Beans (Lima & Snap), Black eyed Peas, Carrots, Cucumbers, Jicama, Melons (Cantaloupe, Muskmelon), Okra, Green Onions, Peanuts, Radishes, Summer Squash, Sunflowers

    Plant Transplants

      Jerusalem Artichokes

    Include edible and cut flowers in your vegetable garden. In addition to adding beauty they will attract beneficial insect pollinators which will increase your fruit set.

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Don't List . . .

    Do not prune citrus except to remove dead or damaged wood and branches obstructing pathways, views, or structures.

    Do not use pre-emergent herbicides in an area in which you intend to plant seeds.

    Do not plant seeded Bermuda until the soil warms up in mid to late May.

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Frequently Asked Questions
Damage is Noticed on the Fruit

Damage is Noticed on the Leaves

Damage is Noticed on the Stem or Trunk

Damage is Noticed on the Roots
    Cultural \ Environmental Questions Insect/Pest Questions Disease Questions

    To Gardening & Landscaping in Maricopa County, AZ

    Timely Tips for April in the Low Desert University of Arizona Logo
    visitors since April 1, 1999
    Last Updated January 8, 2006

    © 1999 The University of Arizona, College of Agriculture and Life Sciences , Cooperative Extension, in Maricopa County. Comments to Maricopa-Hort 4341 E. Broadway Road, Phoenix, AZ 85040, (602) 470-8086 ext. 301