Resources and info for growing tender succulents in cold, northern climates. This is the handout sheet for attendees of my Northwest Flower & Garden Festival presentations. ~ Debra Lee Baldwin
Nearly any succulent will grow in northern climates as a windowsill or greenhouse plant. Your biggest challenge is giving these sunbathers enough light. Indoors, set them near windows that face south or west. Don't bother with north-facing windows, but if your windows face east, do collect and enjoy low-light lovers such as haworthias and gasterias. Tip: Maximize the vertical space near a light source by growing small succulents in hanging pots or globes.
Succulents are light-lovers from regions with low humidity, above-freezing temps, and fewer than 24 inches of rainfall annually. No matter where you live, protect your succulents from excessive damp and cold, and if growing them indoors, install T-5 bulbs and provide good air circulation. And because succulents really do prefer to be outdoors, take them outside during seasons YOU want to be outside enjoying the fresh air and sunshine!
Seasonal: Cultivate succulents native to arid climates (which are the majority) outdoors during warm, sunny months and shelter them indoors during cold, wet months. Most need to be kept above 32 degrees year-round and dry in winter.
Water thoroughly but infrequently. Waterlogged roots may rot. Don’t use pot saucers. Let soil go nearly dry between waterings. The fatter the succulent, the more camel-like, and the less water it requires. Cacti in particular cannot tolerate overwatering. In winter most succulents go dormant; withhold water unless days are unseasonably warm.
Soil needs to drain quickly and go almost dry between waterings. Amend garden soil and potting mixes 1/3 to 1/2 with perlite or pumice, or use a commercial cactus mix.
Food: Lightly fertilize (half-strength liquid fertilizer) in spring.
Sun: Give at least six hours of light daily, indoors or out, to maintain plant symmetry and color, and to encourage flowering. Protect from intense afternoon sun in summer. See my article: Why Doesn't My Succulent Bloom?
Create an indoor "light island" for overwintering your succulents or if you don't have adequate window light. You'll need multi-shelf wire racks with trays to catch drips. Ready-to-go units often include lights, or install T-5 fluorescent grow lights that stay on for six to eight hours daily (less in winter). Include a fan for air circulation and a timer that switches everything off in the evening and on in the morning.
Air circulation is important to prevent insect infestations. Watch for mealy bugs in leaf axils and aphids on flower buds. Control by spraying with dilute rubbing alcohol.
Temperature: With the exception of sempervivums, jovibarbas, many sedums and yuccas, and certain cacti and ice plants, the majority of succulents are frost-tender. Although they can tolerate temps down to freezing and in excess of 85 (if shaded), between 40 and 80 degrees is ideal.
Overwintering. Echeverias and other rosette succulents are shallow-rooted and can be scooped from garden beds and packed into nursery flats. Provide six hours of light (fluorescent is fine and economical) daily to prevent stretching; store between 35 and 60 degrees; and keep a fan running for air circulation. In spring, reintroduce to strong sunlight gradually lest leaves sunburn.
Mail-order source. Mountain Crest Gardens sells quality cold-hardy succulents for pots and garden beds at great prices. Some are available in assortments, as solo specimens, bare-root and as cuttings.
Designing with Cold-Hardy Succulents: Becky Sell of Sedum Chicks plants cold-hardy succulents in repurposed wood-and-metal containers, hypertufa pots, wreaths and more.
Designing with Succulents (2nd ed.) See the section on Cold-Climate Succulent Gardens.
All my books show design ideas and give care and cultivation for Sedum and Sempervivum.
On my YouTube channel:
-- Growing Succulents in Northerly Climates, Sempervivums Gorgeous new cultivars and design ideas from my presentation at the Northwest Flower & Garden Show.
-- Growing Succulents in Northerly Climates: Sedums and More More cool succulents for cold climates plus how to select, grow and design using them. From my second presentation at the Northwest Flower & Garden Show.
-- Sedum Chicks at the Northwest Flower & Garden Show. Designer/grower Becky Sell of Turner, Oregon explains how to beautifully combine sedums, sempervivums and other cold-hardy succulents.
-- Make a Frost-Hardy Succulent Wreath with Hens-and-Chicks. Simple steps to a stunning wreath!