Garden Status in Spring

I walked through my garden, not to pull weeds or pursue other tasks, just to see what was happening. A routine status check can be useful in establishing priorities for the next stretch of sunny days.

Roses

These plants are coming into bloom rather late, compared to roses in warmer areas. The Monterey Bay Rose Society held their annual Rose Show May 4th when my roses were definitely not ready for display. They seem to be coming along just fine, however.

I always anticipate the display of one rose in my garden, a very vigorous rambler (R. mulligani) that blooms in the summer, after other roses, or that I learnt reading online in different blogs such as the andersfogh site that have information about this or many subjects. As described by Christine Allen of Great Plant Picks, “Although its individual flowers are small and single, they appear in such huge, pendent trusses that they cover the entire plant and cast their fruity fragrance far across the garden.”  

Irises

The irises also seem to be a bit later than usual. The American Rose Society’s annual convention (San Ramon, late April) included a tour of Jim & Irene Cummins’ exceptional iris garden in Scotts Valley. The garden was dazzling as always and the tour was successful, but not all the plants had reached their bloom peak. In my garden, I’ve developed a swath of a prize-winning bright yellow iris, That’s All Folks, with a complementary swath of blue irises. The idea worked only half-way because the blue irises didn’t bloom at the same time. Maybe next year.

IIris and Geranium Blossoms
Hybrid Tall Bearded Iris ‘That’s All Folks’, with Geranium maderense in background

The Monterey Bay Iris Society had its annual show on May 4th (same day as the rose show), so my yellow irises at least were blooming on schedule. Iris expert Joe Ghio reported an exceptional year for irises, with peak blooms around May 10th.  He provided these culture tips for this time:

“Snap out or cut out spent stalks and dig pesky weeds. If you want to give your irises a bit of a boost, sprinkle a LIGHT, emphasis light, application of a balanced fertilizer. You can give a regular watering up to late June.”

I will do that!

Lavender

My Mediterranean Basin garden has numerous lavenders, which are iconic plants for that part of the world. Happily, they were cut back at the right time and are now setting a proliferation of buds that will provide color and fragrance during the coming weeks. Lavenders perform reliably and well when they are treated well. The recommended treatment includes full sun, minimal irrigation, and timely pruning, twice each year. The first pruning is promptly after the first flowering, and the second is in late August after the last flush has faded. Cut back about two-thirds of the plant’s height and do not cut into the woody part of the stems.

Salvias

I wrote recently about a seasonal hard pruning of the many salvias in my garden. I did not prune some selected plants for various reasons, but the pruned plants now are already generating new growth. When they bloom, I will resume my project to identify and map the plants that I don’t already recognize.

Meanwhile, I have been learning about the pruning requirements for four kinds of salvias:

  • Deciduous or semi-evergreen types with soft stems, e.g., Mexican Bush Sage (S. leucantha);
  • Deciduous, woody-stem varieties, e.g., Autumn Sage (S. greggii);
  • Evergreen, woody species (the largest category in my garden), e.g., Karwinski’s Sage (S. karwinskii); and
  • Rosette-growing, herbaceous perennials, e.g., Hummingbird Sage (S. spathacea).

For more on this topic, visit the Flowers of the Sea website. Very helpful!

Some time ago, for my South African garden, I planted a Beach Salvia (S. Africana-lutea), one of the evergreen and woody kind. It grew enormously wide among other plants, so I decided to cut it back severely and control its re-growth. After some serious pruning, we discovered that some of the plant’s lower branches had rooted and established new plants, so that its several offspring created the overall width. I now need to reduce my Beach Salvia grove to create room for other plants.

I have another South African salvia, Blue African Sage (S. Africana caerulea), which doesn’t grow quite as large as the Beach Salvia. One can control the size and form of both of these South African species at any time of the year by cutting back the oldest wood.

On a future occasion, I will survey the status of several other plants that grow in quantity in my garden. All gardeners should consider an occasional unhurried survey of their gardens to gain familiarity with what is going on and planning for future maintenance and improvement. A well-known principal of workplace supervision is “management by walking around.” The same idea applies to the garden. The good news is that the gardener can conduct this supervisory function while carrying a beverage of your choice.

Pruning Lavender

Pruning chores can frustrate gardeners when they are unsure of their knowledge. While they might understand that pruning improves the plant somehow, after they have devoted time and energy to growing the plant, trimming the plant’s growth might seem counter-productive.

Pruning the lavender plant puzzles many gardeners, so let us take a look at best practices.

We prune lavenders to stimulate new green growth, which produces flowers, and to slow the formation of older woody growth, which does not produce flowers. Traditionally, we prune lavenders to compact mounding forms that look attractive and yield maximum blooms.

There are two good times of the year to prune lavender plants: in the early spring, before they begin seasonal growth, and in the late summer, after their bloom period. Fall begins on September 22nd, so now is pruning time.

Here is a way to confirm that your lavender is ready to prune. Take a break in the garden, sit quietly near your lavender plant(s) and watch the bees. If they flit from blossom to blossom without lingering to feed, you will know that the blooms are finished for the year and it is pruning time.

Pruning shears will do the job, but use hedge shears to make quick work of pruning. When pruning several lavender plants, an electric hedge trimmer will be the tool of choice.

In any case, ensure that the pruning tool is sharp enough for clean cuts, and wipe it down between plants with rubbing alcohol or bleach to remove any harmful bacteria or germs.

When pruning, remove about one-third of the green growth to stimulate new growth. Do not cut into the woody stems: they will not produce new green growth and cutting too deeply could kill the plant.

If you have the time and patience for precision pruning, cut just above the third node above the woody part of the stem. Most gardeners will keep this rule of thumb in mind without actually counting nodes on each stem.

This process should be repeated in the early spring.

Start this twice-yearly pruning schedule when the plant is still young, i.e., the second year after putting a new plant in the ground. This delay allows time for the plant to establish its roots.

Gardeners might encounter a lavender plant that has not been pruned routinely for three years or more and has become rangy and unattractive, with long woody stems and minimal blossoms. Sadly, the plant cannot then be pruned to rediscover the preferred tight mound form, and should be replaced.

With these guidelines, the gardener will find pruning lavenders quick and easy, and finish the task with a nice fragrance from the lavender’s aromatic oils.

Enjoy your lavender!

More.

There are minor differences in pruning recommendations for the various species of lavender. For this reason, the gardener should be aware of the particular species that is to be pruned.

The most popular species of lavender for residential gardening are English Lavender (Lavandula angustifolia), French Lavender (L. dentata)  and Spanish Lavender (L. stoechas).  Another form that may be seen is Lavandin or Hedge Lavender (L. x Intermedia), which is a cross (hybrid) of English Lavender and Spike Lavender (L. latifolia).

English Lavender’s flower petals unfurl along much of the length of its long stocks. Its green, narrow leaves largely lack the silver and gray cast of the other varieties. It is available in several cultivars. Sunset’s Western Garden Book lists the following: Alba, Blue Cushion, Buena Vista, Compacta, Hidcote, Jean Davis, Lady, Martha Roderick, Melissa, Munstead, Rosea, and Thumbelina Leigh. A light pruning after early-summer flowering often will promote reblooming later in the summer. In late summer, cut back to one-third or even one-half of stem length, as outlined above.

French Lavender has looser-looking, light purple flowers. Their grayish leaves appear more serrated (or dented) than those of their Spanish cousin (the specific name dentata means “toothed”). Prune after flowering remove about one-third of stem length.

Spanish Lavender has tight, deep purple blooms that are shaped like pine cones. Four petals reach skyward, distinctly shaped like rabbit ears. The flower spikes are highly compressed and surmounted by showy, large, sterile bracts. Some varieties have white flowers. The bushes grow about 18 inches tall, with silvery-green leaves. Cultivars include Hazel, Kew Red, Otto Quast, Willow Vale, Wings of Night and Winter Bee.

Hedge Lavender cultivars are Abrialii, Dutch, Fred Boutin, Grosso, Provence, Silver Edge, White Spikes, and others.