Cultivation - Updated 3/7

Geoscape Desert Nursery
Cold hardy cactus, succulents & perennials for the rock gardening enthusiast.
1-208-884-1251 ( voice mail )
Selection & Planting Guide
Step 1of 3: Determine your zone hardiness. Remember this includes both heat as well as cold tolerance. If your not sure what your zone is I've provided a link to the USDA Zone Hardiness map. This will open a separate window.

Click Here for USDA Zone Hardiness Map link

Once there, enter your zip code to determine your zone. On all plant list pages, each plant description will list the compatible zones for that plant, such as Z4a-7a. The further the plants are grown outside of these parameters, the more likely the plant can be lost from excessive heat or cold exposure. Also keep in mind if your growing in containers to shave one full zone off the hardiness scale. This is because the whole plant ( roots and all ) are fully exposed above the ground level and are less protected from extreme weather unless taken indoors.

Step 2 of 3; Determine your soil composition.  All of the following mixes are formulated for optimal drainage based on the average annual rainfall for your area. Most desert plants are water sensitive and therefore all planting beds should be raised a minimum of two to three feet above the ground level for the best drainage. See the rain map further down the page for reference. Mix should be a minimum of 8 inches deep, then an equally deep half & half transition layer over the native soil. If your native soil is a heavy clay type then the minimum depths should be increased to at least a foot or more.

Pea Gravel & Sand: Can be purchased by the cubic yard at your nearest gravel pit for larger landscapes or by the bag for smaller applications from most nursery outlets. Note: When purchasing sand, make sure that it's a "washed" ( no dirt ) product, where water is used in the screening process verses a dry screen. Dry screened sand ( including road mixes ) contains too much dirt fines and will only make a good recipe for concrete. Good alternatives to pea gravel are crushed cinder fines or decomposed granite if you have local access to them.

Potting Soil: Pretty much any organic brand will do for adding active microbes and natural fertilizer. For desert plants use very sparingly in your mix. Too much can increase the risk of root rot and, or fungus.

* Trace Minerals : A product called Azomite is a good quality trace mineral blend that helps balance out any mineral deficiencies that may be missing in your mix that encourages more rigid growth and improved disease & cold resistance. This product is not common in most local stores but is widely available online. Recommended additional mineral products to purchase are Gypsum ( for vigor and & cold resistance ), Superphosphate ( to stimulate flowering and strong root growth ), and Dolomite Limestone ( mostly calcium based also for more rigid growth and disease resistance ). A blend of these ingredients lightly dusted over the surface at the time of planting or annually in early spring is all that's needed.

Amazon links here:
Azomite - Here
Gypsum - Here
Superphosphate - Here
Dolomite Limestone - Here

Fertilizers: Rose & tomato fertilizers contain high amounts of calcium beneficial for cacti. In addition they improve flowering and growth rate and are best applied in late winter to early spring just as the plants are coming out of winter dormancy and showing first signs of growth. Their only drawback is odor with most being a fish emulsion product which can persist for weeks before fading. A non stinky alternative is any good general lawn ( herbicide free, preferably organic based ) fertilizer will be sufficient in combination with the above described trace minerals.

Step 3 of 3: Transplanting prep & procedure.

Cactus plants: Best transplanting temperature is above 80+ degrees F as daytime highs. Rooting can still be done below these temperatures, but can take much longer and is not advised below 60 F as daytime highs.  Make sure the cactus soil mix is mostly dry with just a hint of dust separating when dropping a handful into the air. If no dust separates, then the mix is too wet and more dry mix should be added. Stir up and allow to dry out more if your out of extra dry mix. Once a little dust begins to separate out, then proceed with planting.

Important Note: Cacti are water sensitive and should not be watered immediately after planting. Allow the mix to dry completely to a depth of 3 or more inches before lightly watering. After 6-8 weeks, the new roots should be formed and a deeper watering can be done if necessary to compensate for summer heat. Plants can be gently nudged out of the ground every 2-3 weeks to check for progress. Once established ( usually after the first full year ) regular watering is only necessary if natural conditions are abnormally hot or dry while the plants are actively growing, typically between the end of March until about mid August for most areas. Allow the soil to dry completely to a depth of 3 or more inches. Discontinue any watering in late summer to harden off for winter.

Succulents & Perennials: Best transplanting temperature is between 50-70 degrees F as daytime highs. Plants need the cooler temps of early spring and fall to minimize dehydration of the leaves and stems from the heat of summer. Unlike cacti, succulents and perennials should be lightly watered in immediately after planting. Allow the soil to dry to a depth of 3 or more inches between watering. This is critical during the first one to two years to get the plants established. Once established, watering should only be necessary if natural conditions are abnormally hot or dry. Discontinue any watering in late summer to harden off for winter.

Soil mix for higher water demanding ( semi-riparian to riparian ) desert perennial plants:
Note: On the Perennials Page, this refers to most plants with a "Sandy Loam" soil mix description. This group of desert plants like their roots damp to moist at all times during the heat of summer to maintain hydration or flowering and are adapted ( or adaptable ) to richer soils than their open desert counterparts.

For these plants mix equal parts sand, gravel , potting soil &  your own native soil to retain more moisture. Also for this reason the plants don't need to be elevated above the ground level like true desert plants that demand sharp drainage unless you have more than 40 ( rough threshold ) inches of annual rainfall.

In drier areas below 20 inches per year, a deeper, wider planting hole is recommended to 1 1/2 to 2 feet deep ( keep mature plant size in mind for width ) so that the plants are placed into a slight depression 3-6 inches below the average ground level ( when finished backfilled ) and topped off with a top dressing of potting soil. This will minimize evaporation in the root zone and keep the water confined to the planting hole when watering.
Quick Reference Maps:
Less than 15 in. per year

9 parts pea gravel.
3 parts washed sand
1 part potting soil
*trace minerals
16-30 inches per year

16 parts pea gravel
3 parts washed sand
1 part potting soil mix
*trace minerals
30+ inches per year

25 parts pea gravel
3 parts washed sand
1 part potting  soil mix
*trace minerals