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.
Design trends

Early March in the Garden

Forsythia ‘Kolgold’

Almost overnight, although maybe I’m judging by rain storms, spring is upon us. The birds sure know it is and I’m seeing trees in bloom and new growth on the perennials. The tree frogs are croaking and looking for mates, the weeds are happily trying to grow and set seed before we notice them. But whether you want them to or not all gardens change with time. It’s part of nature that the fittest survive. Possibly you have different ideas of what you want your garden to look like but it’s hard to fool Mother Nature.

I don’t have my Blireiana flowering plum anymore but it was a tradition for me to pose next to it with my birthday presents in late February. It was one of my favorite early spring blooming trees with double pink blossoms and a sweet fragrance strong enough to scent the garden. We look forward to the earliest flowers of the new season knowing that winter will soon be over. Spring doesn’t officially begin until March 20th but hey, we live in California.

Old fashioned shrubs like flowering quince and forsythia figure prominently in many old gardens because they are tough plants able to survive neglect and still look beautiful. The bare stems of forsythia are completely covered with deep golden-yellow flowers in late winter and early spring and become the focal point of the landscape when in full bloom. The showy stems of this easy-care shrub are great for cutting. Forsythia are native to eastern Asia but a chance discovery in Germany by a grower who specialized in breeding for the cut flower industry led to the especially vivid variety ‘Kolgold’ in the 1800’s. Forsythia has long been used in Chinese medicine. The flower petals contain powerful bacteria-fighting properties which make it an important dressing.

Flowering quince is another old garden staple providing early color. They are easy to care for and nearly indestructible in almost any soil that is well drained and not overly fertile. Once established quince is a very drought tolerant plant and their spiny branches make them an excellent choice for hedges, screening or as a security barrier. There are red, pink, orange and white flowering varieties. The Toyo Nishiki cultivar even has pink, white and solid red flowers all on the same branch.

Clivia

What would a shade garden be without a bright orange clivia? Every year I look forward to their huge flower clusters that emerge from between dark green, strappy leaves. Even in dark shade they will bloom and brighten the winter garden although they would do fine in morning sun. If you have a north facing window you can grow them as houseplants. Clivia are hardy to several degrees below freezing but mine, under an overhang, have survived temps of 23 degrees without damage. Clivia breeders have produced gold and peach colored flowers also but I still like the standard orange ones.

Hardenbergia ‘Happy Wanderer’

A beautiful vine that blooms in late winter is hardenbergia ‘Happy Wanderer’. In the pea family, this evergreen vine looks like a small wisteria when in bloom. Pinkish-purple flowers cascade in clusters on twining stems that reach 12-16 feet long. It requires little water once established and is hardy to about 23 degrees. If you have an older, tangled plant you can rejuvenate it with hard pruning in early spring after flowering. Never prune in late summer or fall because you will cut off the wood that is going to bloom the following winter.

The last plant I enjoy at this time of year is Fragrant Sarcococca. The tiny white flowers of this plant are easily overlooked but you can’t miss their scent. I used to have one near the front door that greeted me with that vanilla fragrance every time I walked in or out. The flowers are followed by a bright red fruit. Sweet Box forms a natural espalier against a wall and if you have a problem spot in dry deep shade where other plants won’t grow give this plant a try. They are easy to grow, deer resistant and trouble free.

Enjoy yourself in the garden at this time of year when everything is waking up.

Design trends

Phenology in the Garden

Always on the look out for potential problems in my garden, I can use all the help I can get. Solutions are out there. One of my go-to websites that I use to diagnose those problems is UC Integrated Pest Management or http://ipm.ucanr.edu. You can look up just about anything that may ail you in your garden. As a test, I went to the Plant problem diagnostic tool for Home Garden Turf and Landscape. Talk about a rabbit hole. I was on their site for hours looking up stuff. Try it. Your garden will thank you.

The daffodils are blooming. Will spring be early this year? When will I no longer need to worry about the danger of frost? How much is climate change affecting our natural world? We can all remember years when there was little rain in January and February and it feels like the Bahamas around here. Then there’s this year. The rainy season is upon us. But what are the plants around here doing? Leafing out early? How about those invasive plants around your yard? Look to phenology indicators to give you some insight.

Phenology – not to be confused with phrenology which claims that bumps on the head predict mental traits – is the study of key seasonal changes in flowering times, emergence of insects and migration of birds from year to year. When do they occur each year? Phenology is a real science that has many applications. In farming and gardening, phenology is used chiefly for planting times and pest control. Predictions for fire season are based on factors pertaining to weather as well as plant growth. Certain plants give a cue, by blooming or leafing out, that it’s time for certain activities, such as sowing particular crops or insect emergence and pest control. Often the common denominator is the temperature.

Websites like USA National Phenology Network at http://www.usanpn.org/ offer lots of information on the subject. The US Global Change and Research Program released the first 14 indicators of climate change. Among these is the Start of Spring indicator on this website which reflects the accumulation of heat sufficient to initiate leafing and flowering in temperature sensitive plants. Your own observations via Nature’s Notebook will help contribute to this research.

Indicator plants are often used to look for a particular pest and manage it in its most vulnerable stages. They can also be used to time the planting of vegetables, apply fertilizer or prune. Here are some common garden plants and what they indicate:

When daffodils begin to bloom, sow peas.
When dandelions bloom, plant spinach, beets and carrots.
When lilac leaves are the size of a mouse’s ear, sow peas, lettuce and other cool-weather crops.
When lilacs are in full bloom, plant beans.
Once lilacs have faded, plants squash and cucumbers.
When apple trees shed their petals, sow corn.
When dogwoods are in full bloom, plant tomatoes, peppers and early corn.
When bearded iris are in bloom, plant peppers and eggplants.
When locust and spirea bloom, plant zinnia and marigolds.

When forsythia and crocus bloom, crabgrass is germinating. When this happens the soil temperature at a depth of 4 inches is 55 degrees. Treat with an organic pre-emergent.
When crocus bloom, prune roses and feed your lawn.
Mexican bean beetle larvae appear when foxglove flowers open.

Record your own observations. Another great site is National Sustainable Agriculture Information Service at http://attra.ncat.org. Sites like these can also help you design orchards for pollination and ripening sequence, design for bee forage plantings, design perennial flower beds and wildflower plantings as well as plantings to attract beneficial insects and enhance natural biological control. How cool is that?

Design trends

Allergy Season is Here

My neighbor Sue answered her door sneezing and coughing with puffy eyes and a red runny nose that Rudolph would envy. We live among redwoods and it’s their mating season. Pollen.com predicts pollen levels will increase as alder, juniper and birch release their pollen. Then come the oaks and sycamores. Here are some tips if you love your garden and this beautiful place we call home.

Everybody blames the Acacia tree for their allergies but they are not the real culprits for the allergy sufferer. Redwood pollen is dispersed by the wind. Strong winds blow the yellow redwood “flowers”, which are actually the flowers of the male cone, to release their pollen. Unfortunately because redwoods live in such a narrow band of coast line, there is no allergy shot for those highly affected by them. But back to what you can do in your yard if you suffer from allergies.

Yes, the acacia trees are in full bloom. Being one of the first flowering trees we see they get our attention. Blooming acacias are often blamed as the cause of allergic reactions at this time of year but acacias are largely pollinated by insects and their heavy pollen doesn’t tend to become airborne. It’s the non-showy, quiet plants you have to watch out for. If you’re an allergy sufferer some plants are worse than others for you.

According to historical records for our area the pollen count is mostly moderate in February but don’t tell my friend Sue that. Depending on the weather, www.Pollen.com and www.Pollenlibrary.com show medium high counts only for a few days this month. If you’re an allergy sufferer you don’t need a website to tell you what the count is. Our native red alder is in bloom now and it, along juniper and birch, are the main culprits at this time. Grasses, ragweed and other weeds and most trees bloom and shed pollen in March, April and May. Then comes summer, then fall and with it other problems for the allergy sufferer. To further complicate and make matters worse for the allergy sufferer, climate change is making pollen season longer and more intense. You can’t control what’s growing outside your own yard but here are some tips for what to plant and not plant in your garden.

About 25-30 popular landscape plants are responsible for the majority of plant-related allergies in California. During the height of the pollen season- from late February to June- there are often thousands of pollen grains in every cubic meter of air. One can breathe hundreds of them with every breath. Though pollen can travel many miles, the majority tend to stay in the general area of their origin.

Although California native ceanothus are great plants for the birds and bees, their wind pollinated flowers aren’t so good for the allergy sufferer.

Redwoods, oaks, alders, ashes and other wind pollinated trees like olives, birch, box elder, cypress, elm, juniper, maple, fruitless mulberry, pine, walnut, willow and privet are the major source of spring pollen. Most native plants are good in the sneezeless landscape but if you have bad allergies or asthma it best to avoid wind-pollinated ceanothus, elderberry and coffeeberry.

You may not be able to avoid those culprits growing on other properties but you can get the most out of your own backyard by creating a sneezeless landscape. Replacing existing plants may be impractical but planning future plantings with these things in mind will save you a lot of headaches down the road and let you enjoy the sunshine outside in your garden.

Flower type is a good way to judge plants. The best looking flowers usually cause allergy sufferers the fewest problems. Plants with bright, showy flowers are usually pollinated by insects, rather than by the wind. These flowers produce less pollen and their pollen is larger and heavier, sticking to the insect rather than becoming airborne and lead to sneezing, a runny nose and watery eyes.

Some trees that are good for anti-allergy gardens are apple, cherry, dogwood, magnolia, pear and plum. Shrubs like azaleas, boxwood, lilac, rose-of-Sharon, hydrangea and viburnum are also not likely to cause problems. Good flower choices include alyssum, begonia, clematis, columbine, bulbs like crocus, daffodil, hyacinth. Also good are dahlia, daisy, geranium, hosta, impatiens, iris, lily, pansy, petunia, phlox, roses, salvia, snapdragon, sunflower, verbena and zinnia. Lawns of perennial rye grass, blue grass and tall fescue blends are usually OK as they will not flower unless allowed to grow to 12 inches or higher. Bermuda grass, on the other hand, can pollinate when the lawn is very short, sometimes as quickly as a few days after mowing.

We don’t know what’s going to happen rain-wise for us this spring. Symptoms can become worse for the allergy sufferer if the body reacts to the disappearance of the pollen following its initial appearance only to have to have more of it later in the spring. According to Dr. Stanley Fineman, an allergist with the Atlanta Allergy and Asthma Clinic, “You become sensitized to it, so when you’re…re-exposed, you can get an even more violent allergic reaction.”

Here’s to a sneeze-less spring for you allergy sufferers.