Caring For Cactus

PLANTING AND CARING FOR YOUR CACTI AND OTHER HARDY SUCCULENTS

WHAT IS A HARDY CACTUS?

Plants in the family Cactaceae are all native to North, Central and South America and some Caribbean islands. There are many species even in the coldest regions of these places. The term “hardy” is relative to where you live! For a cactus to be hardy in your area, it must be able to withstand the coldest temperatures that occur where you live. For instance, for a cactus to be hardy in Denver, Colorado (zone 5), where we have our greenhouses, they must be able to withstand temperatures to -25 degrees F. (-35 degrees C.). Other things to consider are: the quality and type of soil you have, the amount of precipitation in summer and in winter and how much sunshine you have. If a cactus doesn’t get enough cold weather, it will not flower normally in the spring.

HOW DO I GROW HARDY CACTI?

SOIL PREPARATION: In the dry climate of Colorado we actually have to water some cacti occasionally for them to thrive. Our soils are typically heavy clays that do not drain well. In most cases we would create raised beds by mounding the soil. To the heavy clay we add 10% composted yard waste and 30-40% coarse sand (1/16th inch to 1/4 inch in diameter). For Opuntias, this soil mixture provides adequate drainage with our average 15 inches of precipitation a year. For species that require better drainage, we add more coarse sand (up to 60%). 

Most of these cacti species prefer slightly alkaline soils. If your soil is acidic, you will have to add crushed limestone or other forms of lime to correct the pH to somewhere between 7.0 and 8.0. If you receive more than 20 inches of rain per year, you will want to increase the drainage material in your soil mix. In extremely wet climates you may have to grow the plants in pots where they can be sheltered from the rain.

HOW DO I PLANT THE CUTTINGS OR PLANTS THAT I RECEIVE FROM COLDHARDYCACTUS.COM?

Opuntias will arrive as pad or stem cuttings. You can plant them in pots or directly in your prepared soil. Using kitchen tongs, lay the pads on their side and press gently into the soil. Roots will form on the underside of the pad and give it a good start. New growth will occur in spring and summer from the edges of the original pad. Alternatively, stick the pad with cut end into the soil so that the pad is vertical. The danger in this is that the wound where it was severed from the mother plant could become infected with bacteria or fungus. Erwinia (potato soft rot) bacteria is the common pathogen of newly planted cuttings. Keep the soil slightly moist until growth begins. 

If you receive plants that already have roots such as Echinocereus, Coryphantha, Agave, Yucca, etc., plant them in pots or in the ground (in your prepared soil mix) with the root origin just at the top of the soil’s surface. Topdress the plant with one inch of crushed stone to support it and to keep the crown drier.

WATERING WINTER HARDY CACTI AND SUCCULENTS

The species we grow and sell may require differing amounts of irrigation. A general rule-of-thumb is that plants from non-monsoonal regions of the dry western United States (plants native to north of Santa Fe, NM) may benefit from bi-weekly watering the first summer, then less to no irrigation thereafter. This includes most ground Yuccas and cacti.

Plant species from monsoonal regions (plants native to areas south of Santa Fe, NM) seem to benefit from more frequent irrigation in July, August and September. This includes most tree-type Yuccas and Agaves.

Hardy cacti and succulents growing in outdoor pots year-around will need water about every 7-10 days in the hot summer months along with fertilization as described below. If you are gardening in a region that receives more than 20 inches of precipitation per year, only irrigate occasionally during excessively dry periods.

FERTILIZATION: Generally, cacti in the ground are only fertilized when young or when you want to encourage fast growth. We recommend using seaweed extract (0.1 % nitrogen) on young plants in the greenhouse and when they are first transplanted into the ground. Once established, over-fertilization can cause excessively tender tissue that can be more prone to winter damage. We always advise a soil test from your local soils lab or agriculture university to determine what type of soil you have and what minerals and nutrients are present or lacking.

Cacti and succulents grown in containers will require regular fertilization, perhaps once a month during the growing months. We recommend dilute seaweed extract, fish emulsion fertilizer or alfalfa meal. Poor tissue color or an absence of flowering may indicate a lack of nutrition of plants in pots.

WINTER CARE FOR CACTI

Most species of cacti would prefer to be quite dry during the winter months. In our region we stop any irrigation in early autumn and don’t resume until late spring. If you get a lot of winter precipitation, shelter plants with a tent or lean-to or grow them in pots and place under the patio in winter.

WINTER CARE FOR AGAVES

If your region gets colder than 0° F in the winter, cover Agave plants with “Frost Cloth” (woven or polyspun white fabric designed for frost protection) in early November. Uncover in mid-March to early April. Styrofoam boxes or rose covers work well also. Cover them every winter for at least two winters to maximize protection. Sudden temperature drops in autumn can damage Agaves before they have acclimated to your climate. After two years, most Agaves will have acclimated. If you are in hardiness zones 4 or 5,  we suggest covering Agaves every winter, forever!