Tuesday, April 08, 2008

April Garden Guide from the Arizona Republic


I don't know if it's OK to quote the whole article but one of my goals in starting this blog was to pull together information like this to help me plan better in future years.

The Arizona Republic credits the following sources for the information in this article:
University of Arizona's Maricopa County Extension, ag.arizona.edu/Maricopa/
Growing Roses in the Desert Southwest, edited by Dona Martin
The Low Desert Herb Garden Handbook, edited by Anne Fischer.

My comments - I don't have grass so I know nothing about the recommendatios for lawns but I left them in for completeness. Don't forget to change your irrigation timer and programming if you have one. I am keeping a log of my settings for future use.

April Garden Guide

The Arizona Republic, Apr. 5, 2008 12:00 AM

Now through October, when plants face the harshest combination of extreme sun exposure and heat, follow a few rules to keep plants irrigated and looking their best.

One rule to especially remember: Deep, infrequent watering is better than a daily sprinkle. What's deep? Watering to penetrate the entire root zone of a plant and no more. Unlike watering a potted plant, where water stays in the pot to be absorbed by the roots, water on the ground doesn't hang out by the root zone indefinitely.

Once water passes the root zone, it keeps on going, wetting the soil, but not benefiting the plant. Although a daily sprinkle might wet the surface of the soil, benefiting shallow roots, the surface is where the plants are exposed to the heat, sun and wind. Deep water encourages deep roots, making a stronger, healthier plant.

When it comes to plant watering, remember: Water to:
  • 1 foot deep for turf, annuals, cactuses, succulents and ground covers;
  • 2 feet deep for shrubs;
  • 3 feet deep for trees.

To measure, start watering the lawn. Take a screwdriver with a long shaft. Jab the screwdriver into the ground and push. If you're nowhere near 12 inches, keep watering for another 15 minutes. Test again.Once you can push the screwdriver 12 inches into the ground easily, stop watering.

Probe tools or lengths of rebar will work for testing water penetration on larger plants. In general, new plants and rosebushes need to be watered more frequently than desert-adapted plants and those that have been in the ground for more than a year. Contact your city water department, or the University of Arizona's Cooperative Extension master gardeners, ag.arizona.edu/maricopa/ or 602-470-8086, to get free literature and advice on lawns and landscaping.


The number of crops to plant declines dramatically - there's just enough to keep many green thumbs happy. Growing veggies and herbs from seed is an inexpensive activity. Follow the seed packet's directions for when and how to plant.

  • Plant seeds of basil, garlic chives, lima and snap beans, black-eyed peas, cucumbers, green onions, melons, okra and summer squash.
  • Transplant basil, lemon grass, lavender, peppers/chiles, mint and rosemary.
  • In hot weather, lettuces and spinach bolt quickly, forming tough seed stalks and causing leaves to turn bitter. Save the seeds for next season, or remove plants and add to the compost pile.
  • For a schedule of vegetable planting dates for Maricopa County, go to ag.arizona.edu/maricopa/.


Before buying a tree to plant on Arbor Day (April25), ask yourself these questions:

  • Am I adding a tree for shade or privacy or to hide an unsightly view or to hang a hammock?
  • Do I want a fruit-bearing, flowering or thorny tree?
  • Do I prefer a tree that keeps its leaves year-round or loses leaves in the late fall?
  • How much time and money do I want to invest in fertilizing, pruning, watering and raking leaves?

Roses may need a few sprays of a fungicide, such as Immunox or Funginex, every week to prevent powdery mildew. A regular application of pesticide, such as Bayer Rose and Flower Insect Killer, can ward off aphid and thrip attacks.

For summer or fall blooms, plant native or adapted flowers such as prairie zinnia (Zinnia grandiflora), desert marigold (Baileya multiradiata) or cosmos (Cosmos sulphureus).


  • Mid- to end of April is the best time to seed or sod bare spots or overseed thinning grass.
  • A good choice for Valley lawns is Bermuda grass.
  • In shady areas plant dichondra, which is not a grass, but a low-growing plant.
  • When laying sod, water well and let grass grow long before mowing.


The well-tended April garden is abundant with growing, blooming plants at their peak.

A neglected April garden can be overgrown with weeds, in need of pruning and watering. Look around and assess what worked, what needs to be moved and which area could use a pick-me-up provided by flowering shrubs, sculptural succulents or ornamental grasses.

  • Plenty of hot months ahead. Check pots to ensure they are not drying out.
  • Add mulch on pots and beds where it has thinned.
  • As conditions dry, ensure veggies and fruit trees do not suffer.
  • Water in the early morning or early evening hours.
  • Tomatoes in particular can fall victim to various ailments if their water supply varies significantly. Place 50 percent shade cloth over tomatoes to keep leafhopper insects away and to prevent curly top virus. The virus affects more than 150 plants in the Southwest, severely stunting and killing vegetable plants. Check citrus trees, whose shallow roots can suffer when conditions are very dry.
  • Continue to deadhead annuals and perennials to promote more flowers.
  • Begin fertilizing Bermuda-grass lawns during late April or early May. Follow directions on the container.

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