Gardening tips for late March in the Santa Cruz Mountains

In like a lion, out like a lamb. This phrase describing refers to the position in the sky of the constellation Leo, the lion, at the beginning of the month and Aries, the ram or lamb, at the end.  As I write this week’s column, the saying rings true so far this month.  Beautiful weather and more daylight hours to enjoy it. What’s not to like?

There’s so much to do now in the garden. If you are feeling overwhelmed here are some suggestions for the more important to-do’s.

* Check drip systems for leaks or clogged emitters. Flush sediment from filters and check screens for algae. You may need to add emitters if plants have grown significantly.

* Finish pruning and clean-up of trees, shrubs, vines and perennials. this includes fireblight die-back on pears, apples, hawthorn, pyracantha, photinia, crabapple quince and toyon., Prune out and discard diseased branches making the cut at least 6-8" below blighted tissue. Clean the pruning blades with a 1:5 solution of household bleach to prevent spread of the disease. Also finish pruning and cutting back perennials and ornamental grasses. Go ahead and give grasses a 3-5" crewcut so fresh growth can emerge. Cut back old foliage of maiden hair ferns to allow new growth to take center stage. If you have Western sword ferns or another type that has winter or thrip damage, remove shabby looking fronds. Even if you have to cut back the entire fern it’s OK. It will regrow in just of couple of months.  Prune any other frost damaged plants when you see new growth begin.

* Spread fresh compost around all your plants. Good soil is the secret to successful gardening. the first principle of organic gardening is to feed the soil and it will feed the plant. Remember that all gardening used to be organic. Layer compost and or mulch on top of the soil and let it slowly decompose and filter down into the earth.

* As you plant new additions to the garden add organic matter to the soil. If your garden’s soil is sandy, organic matter enriches it and allows it to hold water more efficiently. If your soil tends toward heaviness, organic matter loosens it up and improves drainage. In well-amended soil, plants grow deep roots, are hardier and more resistant to disease. Organic matter, like compost, planting mix and well-rotted manure, boosts nutrition and improves soil structure.

* Fertilize if you haven’t already done so. Citrus, shrubs and fruit trees just emerging from dormancy are begging for their first meal of the season. Lawns begin their spring growth now also and benefit from a boost of nitrogen. You can also spread a thin layer of composted manure over you lawn. Leaving you grass clippings on the lawn will benefit it by shading the roots as it get warmer and as they break down they help feed it, too. Perennials benefit from both a fresh layer of compost and a light application of balanced fertilizer. They respond to phosphorus especially in the spring for root growth, stem sturdiness and flower development. Wait until azaleas, camellias and rhododendron have finished blooming before feeding them.

* The most important to-do for March is to take time out and enjoy your garden and our beautiful surroundings. Those last few weeds will be there tomorrow but you’ll never get another today.

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.