Plant of the week – Curl-leaf Mountain Mahogany

grey bark of young branches

I just love Curl-Leaf Mountain Mahogany (Cercocarpus ledifolius) and it is way under-utilized in landscaping!

This xeric shrub – actually more like an architecturally diverse tree when it is happy – survives drought with aplomb and thrives in rocky, poor soils as well as loamy soils.  It is just fine with extreme temperature ranges so it is great if you have a hot, dry spot but it doesn’t mind wind and cold.  Mature plants may reach 30′ in height and are very long lived.  Supposedly one was known to be 1350 years old and succumbed only to a saw.

flowers

Often found on rocky slopes throughout the Western US, it is browsed by a variety of mammals (including cottontails and deer.)  When browsed it becomes bushy and thick but it’s natural habit is upright and slender when young, creating a large multi-branched canopy when mature.

Curl-leaf Mountain Mahogany’s beautiful light grey bark is a terrific background for it’s dark green leaves, which though narrow, elliptical, curved (hence the common name) and rather leathery, are evergreen!  Clusters of yellow-orange trumpet-like flowers cover the branches in early summer.

Curl-leaf Mountain Mahogany shrub

Slender, tapered achenes (seeds) approximately 1/2″ in length have two inch long, curled, wispy awns that make the shrub look like it has curly hair.  Seed production is quite variable depending on the climactic conditions of various years.

This beautiful member of Rose (Rosaceae) family is useful as a focal point of a large garden space or in a landscape setting that calls for a plant with visual movement and interest.  It’s hardy, needs little care and provides green color all year long.

flowering branches of Curl-leaf Mountain Mahogany

It’s time to prune!

Rubber Rabbitbrush needs pruning!

This week we’re pruning the shrubs in our demonstration gardens as the snow melts off but before leaves emerge (yes, we still have snow!).

Pruning

Wax Currant beginning to bud

Pruning maintains the health and vigor of plants by removing dead, diseased or injured material and allows  control of the shape of the plant while promoting fruit and flower yield by concentrating the plant’s energy.

This Rubber Rabbitbrush (Ericameria nauseosus) needs a heavy annual pruning to keep it bushy and under control.   It seems like the more I chop it back, the more vigorous it gets!  Other species like this Wax Currant (Ribes cereum) and our Blue Rock Clematis (Clematis occidentalis) need more careful pruning.

Leaf buds on Blue Rock Clematis

We use very sharp, clean pruning shears on smaller plants and pruning saws on large trees.   Our pruners have been sharpened and bleached in a 10% bleach solution.  It’s important to maintain sanitation and avoid transporting bacteria or viruses on shears.

We prune using the concept of ‘apical dominance’ which means that the plant has a propensity to have one main leader with all the other branches lower than the ‘main’ branch.  Cuts are made just above buds that are pointed in the direction we want the branch to take.  Our goal is to keep plants appropriately shaped (each species has its own form) and to help keep shrubs in the demonstration beds compact.

When to prune:

• Trees and shrubs – ideally after buds swell and before leaves emerge so sap will seal cuts (fall pruning may open the
  

  emerging leaves of Columbine

  plant to disease since no sap is running to seal cuts) but light pruning may be done any time of year

• Grasses may be pruned either after flowering to prevent reseeding or in the fall if you don’t want them for winter interest in your garden.  If you wait until spring (like we have done), prune back as far as you can without damaging new growth.
• Wildflowers may be deadheaded after flowering to promote second blooms or to minimize reseeding, but leave at least half of the plant mass so the plant can accumulate sugar reserves it needs to make it through the winter.  Some flowers like this Blue Columbine (Aquilegia coerulea) need to have old growth removed to make way for regrowth in the spring.

This Mockorange needs to be thinned!

This Mockorange (Philadelpus lewisii) shrub  needs to be thinned out to promote fewer healthy branches rather than lots of spindly suckers.

And of course, pruning provides cuttings for vegetative propagation which is a subject for another blog another day.

Pruning Blue Elderberry