Rhododendrons for the Santa Cruz Mountains

Spring officially kicks off March 20th and if you’re like me every tree, shrub and perennial that starts to flower is an event. The subtle colors of winter are behind us. Bring on the colors of the rainbow.

Rhododendrons are one of spring’s show stoppers. Huge, rounded clusters of stunning blossoms in lavender, red, purple, white, pink and even yellow and gold clothe these shrubs with color. You can have flowers from February to late May by choosing different varieties. And rhododendrons are easy to grow if you give them what they need.

Because rhododendrons like air in the root zone, amend your soil liberally with organic matter.  50-60% is not too much. If you garden in clay, just plant them in raised beds or berms 1-2 ft above the original soil level. Rhododendrons like moist soil so top dress around your plants with several inches of mulch over the root zone, making sure the stem is not get buried. Pine needles, oak leaves or wood chips are good choices. around the plants as this would injure the surface roots. Finally, most rhodies thrive in partial shade or morning sun. The hot afternoon sun that we get during the summer would burn even those varieties that tolerate some sun. Since their leaves remain on the plant for several years you’d have to live with burnt leaf centers and edges for a long time if they got too much sun.

There are thousands of rhododendron varieties. By planting early, mid-season and late blooming types you can enjoy those huge, gorgeous flowers for months.

Cheer is one of the showy early bloomers. Large, pink flower trusses cover the 5×5 ft plant. It can take some sun and would be a good candidate if you have one of those gardens that receives and hour or so of afternoon sun.

For April blooms consider Edith Bosley. Similar to Purple Splendor it grows upright to 6 ft.tall but only 4 ft wide. Perfect for narrow spaces. Other mid-season bloomers that would make a splash in the garden include Golden Gate, a 3 ft compact orange hybrid and easy-to-grow, red-flowering Jean Marie de Montegue.

To extend your season add some late season varieties like Lee’s Dark Purple. Growing with a spreading habit to 4 x 5 ft wide, you’ll love its blue-purple trusses. Anah Kruschke also blooms late in spring with lavender pink flowers on a dense 5 x 5 ft shrub. A tough undemanding larger variety is English Roseum. This one grows 6 ft tall with lavender pink flower trusses and blooms in May.

Rhododendrons really contribute to the woodland or shade garden. They are long-lived and deer resistant. I’ve only heard two gardeners tell me that deer ate some of their flower buds last fall for the moisture content. Most likely those deer couldn’t read well enough to read the deer resistant list!

Gardening zones & last frost in the Santa Cruz Mtns

The weather this winter has been fairly mild. Rainstorms since mid-January have kept the average low temperatures at night from dipping very low. Spring is right around the corner and on time. As your thoughts turn to gardening  make sure those new plant choices are the right ones for your area.

Some gardening tasks are dependent on the weather. Many shrubs,perennials and grasses are to be pruned after danger of frost is past and many vegetables should be started after this time as well. As a reminder the . I’ve kept a weather journal for my area, the San Lorenzo valley, since 1992.  Based on my records, we may get a few light frosts, especially after a storm, in late March or early April but for the most part, we have mostly passed the chance of having a frosty morning. Still it’s a good idea to have a cardboard box or blanket ready to protect your young seedlings.

Knowing the climate in your area helps determine what you can grow in your garden. Notice how much sun or shade an area gets during the growing season, from April through September. Every year I get asked which zone we are in. It’s confusing in Sunset Western Gardening Guide as our area has many microclimates and their map is not detailed enough to reflect this. They even show Felton as being in zone 7 on a ridge top instead of on the valley floor. . Another problem with Sunset’s current book is the typical winter low they show for each of the three zones around here. For example, zone 17 ( Pasatiempo  and the banana belt ) is described as having lower temps in winter than the summit. It’s confusing to both new and seasoned gardeners alike. Here are some tips to help you determine in what zone you garden.

Zone 7
  has the coldest winters in our area.  Very high ridge tops like the Summit area and the most northern portions of Bonny Doon lie in this zone.  My records show average winter lows ranging from 15-25 degrees based on 20 years of input from gardeners in these areas.  This does not apply to other areas of zone 7, just those around here.   Record lows have occurred during freezes in 1990, 1996 and 2007 but as gardeners we rely on average highs and lows to help guide our planting times.  Spring weather comes later in this zone with the growing season mainly from April – October.

Zone 15 – this zone encompasses most of our area.  Winter lows average 20-30 degrees. The valley floor of both San Lorenzo and Scotts Valley lie in this zone and are what I call "a cold 15".  Cold air sinks and is trapped in these areas. Often there is damage to the tips of oleanders and citrus while gardenias and tropical hibiscus need extra protection.There are warmer parts of this zone, though, where the growing season starts in March and ends in November.  These areas rarely get a freeze after March 15th or before Thanksgiving.

Zone 16 – those who live up off the valley floor but below ridge tops live in this "banana belt". Pasatiempo also falls in this thermal zone.  Light frost can occur during the winter but mostly the winter lows in this zone stay above freezing.

I hope this helps in choosing plants that will thrive in your garden.

Last chance for Bare Root in Santa Cruz Mtns

It’s not too late to plant bare root. Except plums which emerge from dormancy early, most fruit and shade trees as well as shrubs  are still available bare root. Good choices include Angel pomegranate and Texas scarlet flowering quince. Lavender Lady lilac would bring delicious fragrance to the garden.  How about adding an accent tree like a Echtermeyer weeping crabapple with purple-red blooms? The birds love the wine red fruit that hand on the tree during the winter. Forest Pansy redbud also look terrific in the garden.  Their burgundy heart shaped leaves turn orange in the fall are an added bonus after bright magenta spring flowers.

If you like unusual additions to your flower arrangements, consider planting French Pink pussy willow. Long silvery catkins covered with a showy pink cap are very colorful in winter before the plant leafs out.

Saturn flowering and fruiting peach continues to be one of the most popular peaches. You can’t beat the excellent quality fruit and the massive large, double pink blossoms are breathtaking.

A small cherry that is easily protected from the birds is . You can have large, dark red, sweet cherries when the tree is still quite young and it’s a good pollinizer for all sweet cherries.

So whether it’s something edible or an ornamental tree or shrub you’re interested in, plant one now while they are still bare root and so affordable.
 

The Mountain Gardener's Weblog