Plant Type: Succulents & Cacti

Succulents offer dramatic shape and architecture rarely seen in our gardens. Whether hardy specimens for rock gardens or as dramatic seasonal plants nothing can beat their exotic structure.  We include yuccas and succulent perennials in this list. There are several tricks to growing some of the more dramatic cold hardy Agaves in our climate. First, they should be planted as soon as the soil warms in spring. Tilt the rosette- this is best on a slope so that winter rain/ice will run out of the rosette and not gather and freeze- causing stress. Give them VERY good air circulation and take away any leaves from deciduous plants that have gathered in the rosette.  Be careful. Some people use a blower, I’ve had luck with a can of air to clean office equipment. Save your hands from the spikes. Ouch.

Amend the soil for success

Normally we aren’t big fans of soil amending. It seems ridiculous for most native plants and its a huge carbon footprint when a truck has to bring you compost. In the case of cold hardy succulents amending is crucial in our climate because of our winter rainfall pattern. To site: Find a slope in full sun and excavate a large amount of the soil and save. Add  medium to large boulders underground and on top. Incorporate  1/2″ minus or any other rough hued gravel into the saved soil and add a small amount of all purpose fertilizer and replace. Plant carefully, its not usual to see people using BAR B Q tongs and ovenmits to handle Cacti and Agaves.  Plant hardy rosette forming plants at a tilt to avoid the accumulation of water/ice into the crown- it should be able to drain away. Plant, water in well. Most succulents grow when its warm so to establish them you should  water them well in the first HOT summer they are in the ground. Roots will penetrate deeper as the soil temperature will be warm too. Let the soil dry completely between watering. For hardy Cacti and Succulents weeds and weed seeds can pose a difficult problem. Eliminating them is painful and tedious at any time of the year. Mulch with gravel and keep up on your weeding, especially in winter when you think least to do it.

Do not leave rocks/leaves in the rosette- it will cause winter rot

Remove all rocks and leaves from the center of the Agave before winter hits. The most efficient way is to use a blower and clean out the duff completely. If leaves are left in the crown they will rot the plant as they decompose. Agaves like to dry off between rainstorms. Put them in a fully exposed site facing south and do not let other plants over top them. This is also fatal. When desperate one of those cans of air to clean office equipment is also useful. Hold it no closer than 1′ from the plant (too close and it can freeze the plant as it is super cooled and can form ice) but at least a foot away you’ll still get enough of an air blast to knock just about anything out.

Winter aridity is the key to hardiness

If you plan on growing your hardy succulents in containers make sure that you don’t pot it into a container that is too difficult to move. Many succulents are very hardy to cold as long as they are dry in the winter. Most come from summer rainfall areas. They prefer moisture when its hot but dryness when its cold. Move containerized plant to a dry spot- under an eave or a cold greenhouse BEFORE  winter rains begin and leaves start to fall. Dryness in winter can afford you almost 10ºF extra` degrees of cold hardiness. Keep them dry in winter. In the ground, this is where sharp drainage and amending pays dividends. Also, Agaves and hardy Cacti are actually tender until they have fully rooted out into the ground. The more roots you have, the better established the better the plant can resist cold and wet. Plant them as soon as it warms in spring and care for them for their first season. Again always let hem dry between irrigation. In subsequent years you can add one handful of all purpose prilled fertilizer each spring.

Location is everything

These plants all need to be sited carefully to succeed. Plant them in hot south facing aspects, on slopes, in hot rock gardens at the base of a hot wall. Even a thoughtfully placed boulder can absorb and radiate enough sun heat that it will offer benefits to these plants. Remember most of these plants are experimental in our climate. Our rainfall patterns that combine cold and wet are anathema to where they grow.  Though they take preparation and thought very few plans offer as much bold structure and simplicity. They are worth it.

Climate Adapted Plants for Gardeners in the PNW