Desert Gardening Basics: Planting Tips & Seasonal Guide

1. SaddleBrooke/SaddleBrooke Ranch Master Gardeners present: Basics of Desert Gardening Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Jeffrey C. Silvertooth, Associate Dean & Director, Economic Development & Extension, College of Agriculture and Life Sciences, The University of Arizona. The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.

2. Welcome to the Desert!

3. The Challenges and the Rewards • Low rainfall, extremes of temperature and weather, wind, sun, heat, rocky clay-based alkaline soil, maybe even caliche, virtually no organic matter in the soil. • But: a 12 month growing season, ability to grow semi-tropicals, cacti & succulents, citrus, fruit trees, and so much more!

4. At the Beginning • Do you have a brand new landscape, or have you inherited one? • How much work do you really want to do? • Professional design, installation and maintenance? • All DIY? • Some combination of the above?

5. Take it slow • Start slow! Take the time to understand your property and how it is affected by sun, wind, etc. • Make a wish list – not just of plants, but for hardscape and the purpose of your garden • Visit botanical gardens, demonstration gardens, go on garden tours, read books, visit nurseries

6. First Steps • Plan and install your hardscape before planting. • Determine the proper watering durations and intervals for your plant choices. • How many valves? Do you need a new controller or a completely new system? You can get very complex, but typically you need tree, shrub and flower capabilities, and possibly a dedicated container line.

7. Deciding On a Garden Style • Easy care? • Specific plants? Sonoran natives, desert adapted plants from many regions of the world, wildflowers, vegetables, cacti and succulents ? • Privacy? Windbreaks? Fragrance? Pool and/or spa? How much hardscape?

8. Things to consider before planting • Do you have a view to preserve or accent? (or block?) • Are you a snowbird? Maybe you don’t want to focus on plants that will bloom while you are gone. • Do you want to encourage birds and pollinators? • What is your tolerance for critters, insects, etc.? • Do you want to choose marginally hardy plants and have to cover them several times during the winter?

9. Our 5 seasons • Spring: February to April • Dry Foresummer: May & June • Monsoon Season: July to mid-September • Fall: Mid-September to November • Winter: December and January

10. Dealing with our 5 seasons • The best time to put in new plants is in the fall.* • Winter rains are typically slow and gentle. • Monsoon rains are intense and localized. Much of this water runs off before it can be absorbed. • Summer is the most challenging time for our plants. • Reduce your irrigation frequency in the winter. • Yes, you have to understand your irrigation controller! * Cacti, palms & tropicals can be planted in spring as they want warm soil.

11. How to site your plants based on exposure to the sun • Full/reflected sun: tough plants that can withstand south or west exposures, plus heat reflected off a wall or window. • Full sun: will tolerate exposure to 8 or more hours of sun per day. Even natives and cacti will appreciate some afternoon shade, such as under a tree canopy. New plantings will benefit from shade cloth for their first summer.

12. How to site your plants based on exposure to the sun • Partial sun: these plants should be protected from afternoon sun. Use an eastern exposure, or filtered sun beneath the canopy of trees. • Shade: Northern exposures, deep shade beneath trees, or next to a north facing building or wall.

13. Watering • If you have an original irrigation system that is approaching 10 years old or more, the mains will begin to leak. Consider replacing mains with PVC pipe, which has a much longer life. • Try to group plants with similar water needs together. • Creating zones will make the irrigation layout much easier.

14. Water Requirements • Every plant, even those that will grow up to be low water usage, will require regular irrigation until established. • Every plant label includes the phrase “once established”. • Assume “established” means having survived one or two summers.

15. Water Requirements • When a new plant is put in the ground (except cacti), you need to keep that original root ball size in mind, and hand water it regularly, even daily, until you see new growth. Then you can begin to “wean” it gradually. • Better to water trees and shrubs slow and deep instead of running the irrigation for a few minutes every day. This encourages the roots to grow downward. The plant will then be better anchored in the ground and more able to withstand dry periods and high winds.

16. Where to place your plants • If you have a pool and/or spa, or patio surfaces nearby, look for plants that produce little or no litter. • Elsewhere in the garden, litter is not bad; it is free organic matter, and our soil could certainly use all it can get. • Usually, litter is seasonal, like seedpods, flowers, or leaf drop. • Spiny and thorny plants are best placed away from walkways. However, they can also provide significant security at the perimeter of your property, as well as wildlife habitat.

17. Micro-climates • Wind, south and west walls, north wall, east wall, sloping ground, cold air pockets, eaves, shade trees and over-hanging structures, dry banks • Take note of these in your yard, and select plants that will be able to survive and thrive in these locations. • Plants near the south and west walls of a home can be one zone warmer than the rest of your yard.

18. Micro-climates • Example: cold air drops, so the top of a slope is more forgiving than the bottom, especially if there is also a wall at the bottom to trap and hold the cold air. • Very cold air moving over a plant does much less damage than when that air stops.

19. Pruning • Your trees are a major investment and landscape feature. • Do not trust their health and form to an amateur – use a licensed arborist.

20. Pruning • Continual shearing of plants not only removes flowers, but eventually kills the interior of the plant, as sunlight cannot reach the interior. • Better to accurately assess the space you have available and choose a plant that can maintain its natural form rather than constantly try to subdue something that wants to be 8’ wide and is in a 2’ wide walkway.

21. Pruning No shrubs wider at the top than the base; base of plant will die out from lack of light.

22. Pruning • Consider the plant’s mature height and width; this will minimize the need to continually prune to control size.

23. Pruning equipment • Bypass pruners – the best one you can buy is a Felco, and they are available for lefties as well. The No. 9 is the “gold standard”. • Never use anvil style pruning shears. • Loppers for branches of large diameter; also look for bypass style. Anvil style should only be used on dead wood, as it crushes the wood. • Really look at the plant, and step back often as you work. • If you are dong it properly, you do not have to do it that often!

24. Some cacti tips! • Make sure your cacti are not downhill of a plant on irrigation. • The dot or “X” on a cactus pot almost always indicates the south facing side (check with the grower). It has thicker skin on that side, so make sure it goes in the ground with that side still facing south. Yes, cacti can sunburn, and it isn’t pretty. • Therefore, do not rotate cacti in pots… • Give cacti a week in the ground before you water, in case any roots were damaged. You do not want them to rot!

25. Shade Cloth • A good idea to have shade cloth (30%) ready for a plant’s first summer in the ground; especially cacti • Sunburn on cacti is permanent • Shade cloth or a shady spot for any plant coming out of a greenhouse This Photo by Unknown Author is licensed under CC BY-SA

26. Insects • If you want to make your pest problem worse, spray with chemicals • Put up with some cosmetic damage • Be observant • Aim for diversity in plantings to attract beneficial insects • 97% of insects are beneficial or neutral • Make sure you know the difference between friend and foe • Chemicals are non-selective; they kill all insects • The problem ones return first, and with a vengeance

27. IPM (Integrated Pest Management) • Use the least damaging methods first: • A jet of water • Hand picking • Insecticidal soap, but this will also kill beneficials • Healthy plants are less bothered by insects and disease • Are you watering properly? • Is the plant struggling in the wrong location? • Are you working on making healthy soil?

28. Creating healthy soil • No longer advisable to amend just the planting hole • But you can amend a large area like a flower bed or raised vegetable garden • And you must for vegetables, roses, and some other plants • Native and desert-adapted plants will make your life easier! • Spread compost around bases of plants twice a year (Apr., Oct.)

29. Organic Matter • Soil cannot be healthy without billions of microorganisms, fungi, insects, etc. • The above must eat something! • That something is organic matter! • Compost is the holy grail. • Make your own, or • Buy Tank’s Green Stuff; it is certified pathogen free and will not introduce disease or weed seeds to your garden

30. Some planting tips! • Dig your planting holes wider than your plant, but no deeper. A plant should end up at the same level it was growing, or even a tiny bit higher to account for settling. • Native trees and shrubs do not require fertilizer, nor do you need to amend the soil at planting.

31. Frost Protection • Can be purchased online, or at B&B Cactus Farm by the yard • Cut to size, store completely dry, and it will last for years • Try to not let it rest on the top of the plant; support with bamboo stakes • Bring to the ground and use rocks to hold in place • Clamps, clothespins, bungee cords help it stay in place during high winds • Styrofoam cups for tops of sensitive columnar cacti such as Mexican Fence Post and Organ Pipe

32. Some citrus tips! • Do not prune your citrus except to remove dead, damaged or crossing branches. They are meant to have branches almost sweeping the ground, as this protects their trunks from sunburn. • If it’s too late for the above tip, paint the exposed trunk with white latex paint. • There is also a brown tree paint called Go Natural.

33. Some more citrus tips! • When planting citrus, note the “bump” near the base of the trunk. That is the graft union, where the desirable top of your tree was spliced into a very hardy and disease resistant rootstock. • Plant so that the “bump” isn’t facing south or west. • If you see growth arising from below the graft, remove it. The fruit will not be tasty and there will usually be wicked thorns! • Order of cold hardiness in citrus from least to most: lime, lemon, orange, grapefruit, kumquat.

34. Remember! • It is very different here, and yet it is still just the control of light, soil, temperature and water! • If you do your homework, a plant wants to survive, and you will have a beautiful garden!

35. Resources: • Botanical Gardens • Tucson Botanical Gardens, 2150 North Alvernon Way, Tucson AZ 85712, 520.326.9686, tucsonbotanical.org • Tohono Chul,7366 North Paseo del Norte, Tucson AZ 85704, 520.742.6455, tohonochulpark.org

36. Resources (cont.) • Books • Desert Gardening for Beginners by Arizona Master Gardeners • Arizona Gardeners Guide by Mary Irish • The New Sunset Western Garden Book from Sunset magazine

37. Resources (cont.) • Nurseries • Mesquite Valley Growers, 8005 East Speedway Blvd., Tucson AZ 85715, 520.721.8600 • Desert Survivors Native Plant Nursery, 1020 West Starr Pass Blvd., Tucson AZ 85713, 520.791.9309, desertsurvivors.org • Rillito Nursery and Garden Center, 6303 North La Cholla Blvd., Tucson AZ 85741, 520.575.0995, rillitonursery.com

38. Resources (cont.) • Nurseries • Bach’s Cactus Nursery, 8602 North Thornydale Road, Tucson AZ 85742, 520.744.3333 • Civano Nursery, 5301 South Houghton Road, Tucson AZ 85747, 520.546.9200, civanonursery.net • B&B Cactus Farm, 11550 East Speedway, Tucson AZ 85748, 520.721.4687, bandbcactus.com

39. Resources (cont.) • Websites: • Arizona Municipal Water Users Association: AMWUA.ORG , Landscape Info • Wateruseitwisely.com for interactive plant watering guides • Ag.Arizona.edu for links, info, plant lists, etc.

40. Resources (cont.) • Other: • Drive around and look at your neighbors’ gardens • Attend Home and Garden Tours • Pima County Cooperative Extension Demonstration Gardens, 4210 North Campbell Ave., Tucson AZ, 520.626.5161