All posts by Jan Nelson

I am a landscape designer and consultant in the Santa Cruz mountains in California. I write a weekly gardening column for the Press Banner newspaper. I am also a Calif. Advanced Certified Nursery Professional and managed The Plantworks Nursery in Ben Lomond, Ca. for 20 years.
fungal diseases, succulents

Aloe & other Succulents in the late Winter Garden

Usually succulents are bullet-proof in the garden. Easy care, low water and dramatic they are great additions to the landscape. If you are having problems with fungal spots on yours after so much rain and cold you?re not alone. Still aloe, yucca and agave are worth growing as well as other succulents. Here is some useful information.

Cape Aloe

Succulents have demonstrated a wide tolerance to the fungi that cause leaf and some spots. Although they can disfigure plants they do very little damage despite their appearance.

There are other more serious fungal infections like anthracnose. It often appears as a moist tan colored rot with red, orange or pink pustules on the surface. Spots start small, but expand rapidly on both leaves and crowns. Once a succulents is infected the only treatment is removal of affected leaves. The application of copper fungicide may help to destroy fungal bodies. Root and crown rot don?t respond well to treatment and if you have planted your succulents in well draining soil there might not be much you can do about the excessive rain they?ve gotten recently.

Our Mediterranean climate is usually perfectly suited for the exotic looking family of Aloes. Some hail from the Arabian Peninsula and Madagascar but mostly they are native to South Africa. The spikes of their showy flowers supply much needed nectar for hummingbirds now when not much else is blooming.

There?s a variety for any space, large or small, container or tree-like. Here are a few of the types I?m seeing blooming right now in our area.

Aloe ferox

Aloe ferox or Cape Aloe grows best in full sun but tolerates a wide variety of growing conditions. They can thrive in very dry conditions or grow in an area that receives regular irrigation- a good trait given our recent wet winter. The foliage is hardy to at least 20 degrees and the winter flowers down to 24 degrees. Cape aloe grow to 6 feet tall and 3-5 feet wide so plan accordingly if you plant one of these spectacular reddish-orange to orange succulents. Cape Aloe occupies many habitats in its native Cape Region of South Africa and is listed on the endangered plant list.

Torch aloe

Torch Aloe or Aloe arborescens blooms also in fall and winter. The bright yellow or red flower spikes cover this large clumping variety. This species has recently been studied for possible medical uses similar to the well known aloe vera plant. It?s the only other member of the Aloe family that is claimed to be as effective. It can survive much lower winter low temperatures than aloe vera.

Aloe vera has been grown for thousands of years in tropical climates. It is one of the most widely used medicinal plants on the planet. As a houseplant make sure the pot has plenty of drainage holes as they cannot tolerate standing water. Let them go completely dry between waterings and grow them in the very bright light of a south or west facing window.

The Soap Aloe or Aloe maculata is so tough that it can survive just about anywhere. My soap aloe aren?t blooming right now but others in better growing conditions are sporting showy flowers atop tall, multi branched stalks in colors ranging from red to gold. Once established this succulent needs only occasional water to look good. They grow in partial to full sun. The foliage gets 18 to 24 inches tall with the bloom spikes reaching 35 inches tall.

Every garden should have a variety of aloe to feed the hummingbirds in winter.

Arbor Day, trees

Arbor Day in California

California?s Arbor Day is celebrated on March 7th, in honor of famed horticulturist Luther Burbank?s birthday. The day is celebrated on different dates around the world because one of the features of Arbor Day is the planting of trees which is best done at certain times of the year. The simple goal of this day is to inspire people to plant, nurture and celebrate trees.

Second growth redwood fairy ring.

We are fortunate to live here in the Santa Cruz mountains in a temperate rain forest with lots of trees. Our redwoods are especially important in our biodiverse watershed as is all flora and fauna in the forest. Redwoods and many native trees keep our environment moist. Let?s make it a priority to protect them and pass the baton of stewardship to our children who will inherit this place.

So whether you’ve been thinking about planting a redwood, heritage oak or other native tree, a fruit tree to feed the family, a shade tree to save on summer cooling, a flowering tree to attract pollinators, or a tree to hang the hammock on this is a good time to plant as well as nurture and celebrate all trees..

Trees are remarkable in how they grow and adapt to their environment. Some trees, like redwood, ponderosa pine, sycamore and madrone have especially beautiful bark. This is the tree’s protection from the outside world. Continually renewed from within, it helps keep out moisture in rain and prevents the tree from losing moisture when the air is dry. Bark insulates against cold and heat and wards off insect enemies.

The inner bark, or phloem, is the pipeline through which food is passed to the rest of the tree, It lives for only a short time, then dies and turns to cork to become part of the protective outer bark.

The next layer in is the cambium cell layer which is the growing part of the trunk. It annually produces new bark and new wood in response to hormones that pass down through the phloem with food from the leaves. These hormones are called auxins and stimulate growth in the cells. They are produced by leaf buds at the ends of branches as they start growing in spring.

Inside the cambium layer is the sapwood or xylem which moves water from the roots to the leaves. Sapwood is new wood. As newer rings of sapwood are laid down, inner rings lose their vitality and turn to heartwood.

Finally, the central supporting pillar of the tree is called heartwood. Although dead, it will not decay or lose strength while the outer layers are intact. A composite of hollow, needle-like cellulose fibers bound together by a chemical glue called lignin, it is in many ways as strong as steel.

fog filtering through the redwood trees.

Leaves make food for the tree. Their shapes help them reduce wind resistance, shed rain that could decay the leaf if left standing and produce chlorophyll. The narrow needles of a Douglas fir, for instance, exposes as much as three acres of surface to the sun.

Be kind to all trees. They are a valuable asset to your home and our environment. Earth Day is next month on April 22nd. Let?s continue to celebrate the natural beauty of our planet and learn what we can do to keep it healthy.

climate zones, planting tips

Climate Zones

You know when you walk out the door how hot or cold it is, how windy, shady, moist or dry. You know if your soil is pure sand or hard clay because you?ve dug a few holes in your time. You don?t need a book to tell you these things. So why are the gardening zones described in Sunset Western Gardening book important when you add a new plant to your garden ? And why are they so confusing in our area?

Sunset Climate Zones for the Santa Cruz Mountains

We all rely on Sunset’s Western Garden Book as the bible for gardeners. With each new edition I look to see if they’ve figured out that Felton is not in zone 7. Sure Felton gets pretty cold but even with climate change the San Lorenzo and Scotts Valleys are not as cold as a zone 7. Even considering microclimates we can grow a wide variety of plants that would not survive in the Sierra foothills, the Gabilan range, the Coast range or other zone 7 areas. Wish they would ask local nurseries and knowledgeable horticulturist what the weather and climate are really like here.

Knowing the climate in your area helps determine what you can grow in your garden. It’s confusing to both new and seasoned gardeners alike. Here are some tips to help you determine in which zone you garden.

We really only garden in two zones around here – zone 15 and 16. The Sunset map erroneously shows Felton as being in zone 7. Based on my experience even ridge tops like the highest portions of Bonny Doon and the Summit area which gets an occasional dusting of snow fall mostly in a colder zone 15.

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 zone 15. Cold air sinks and is trapped in these areas. There are warmer parts of this zone, though. 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”. Light frost can occur during the winter but mostly the winter lows in this zone stay near or above freezing. You might have cold pockets on your property however so plan accordingly.

Beside the zone you also need to note how much sun or shade you get during the growing season. There may also be microclimates on your property. Are you near the river in a canyon or gulch or up on a south facing slope? Some areas in your garden may be several degrees warmer than other spots such as up against a brick wall or at the top of a slope from where cold air drains. Planting a citrus at the top of a slope that drains away the cold will make your tree much happier than if planted in a low open area.

Soil quality is not taken into consideration in zone mapping. Since the soil houses the water and nutrient uptake system for most plants, it plays an important role. Most plant guides describe soil requirements in terms of well-drained, acid or alkaline, poorly drained or high organic matter.

If you have questions about which zone you are in, email me and I’d be happy to help. I hope this helps in choosing plants that will thrive in your garden.