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

March Tasks in the Garden

California native, Red Flowering Currant is loved by hummingbirds.

A favorite survivor of the CZU fire is starting to bloom this week in my garden. Even though I had to remove the burned pot along with all the branches and roots, my red flowering currant ( ribes sanguineum) recovered to the delight of the hummingbirds. It’s growing in partial shade in a new pot here but would make a good shrub under oaks or other trees. The fruit is a dark purple oval berry which the birds love. This plants hosts several butterfly species. I’m so happy it survived.

This is what I recommend doing in your garden this month.

Weed – Besides enjoying all the early spring bloomers I’m doing a lot a weeding lately. This hopefully will be the last year I have to pull the thousands of self-sowing annual impatien balfourii which are loved by the hummingbirds all summer but geez, each plant produces hundred of viable seeds. Pull weeds regularly before they set seed. They pull out easily from moist soil. Weeds rob your plants of precious water. Think of weeding as free gym time.

Check drip systems for leaks or emitters clogged by dirt or earwigs. Flush sediment from filters and check screens for algae. You may need to add emitters if plants have grown significantly and move the emitters farther away from the crown of the plant and out closer to the feeder roots which are under the drip line.

Fertilize – Citrus may be looking yellow from lack of nitrogen and iron which is not absorbed easily during the cold season. Shrubs and fruit trees just emerging from dormancy are begging for their first meal of the season. Lawns -if you still have a small section- and ground covers begin their spring growth now also and benefit from a boost of organic nitrogen. Leave grass clippings on the lawn to shade 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 the phosphorus from bone meal especially in the spring for root growth, stem sturdiness and flower development. Wait until azaleas, camellias and rhododendron have finished blooming and you see new leaf growth starting before feeding them.

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 2-3″ of compost or mulch on top of the soil and let it slowly decompose and filter down into the earth. Bark nuggets do not increase your soil’s fertility like compost or wood chips do but they do conserve moisture and help keep weeds at bay.

Transplant any plants in the garden that have outgrown their space or are not with other plants requiring the same water usage. Now is a good time because plants are full of growth hormones and recover quickly from transplant shock. As you plant new additions to the garden add organic matter to the soil if it’s sandy. Organic matter enriches and allows it to hold water more efficiently. If your soil is sandy, organic matter will allow your soil to hold more moisture longer. If your soil tends toward clay, organic matter will loosen it and improve drainage. In fertile soil, plants grow deep roots, are hardier for cold, more resistant to disease and more drought tolerant. Organic matter such as compost, planting mix and well-rotted manure boosts nutrition and improves soil structure.

Check for aphids. They are out in full force sucking plant juices from the tender new leaves of everything from roses to hellebore to Japanese maples. A strong spray from the hose may be enough to dislodge them. If they still persist, you can spray organic insecticidal soap, neem oil or horticultural oil to kill them. As with all pesticide sprays, do this early in the morning or later when they are not in the sun. Be sure to test first to make sure the spray doesn’t burn the new growth and always mix according to the directions.

The most important to-do 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.

Design trends

Green Isn’t Just for St. Patrick’s Day

Choiya ternata ‘Sundance’ sports lovely chartreuse green foliage

Wearing something green on St. Patrick’s Day has been a tradition since immigrants, particularly in the United States, transformed the holiday into a largely secular event celebrating all things Irish. Cities with large numbers of Irish immigrants staged parades going back to 1737 in Boston and in New York City since 1762. Although blue was the color traditionally associated with St. Patrick, green is now commonly connected to this holiday with shamrocks high on the list of things to wear on this day.

On Thursday, March 20th at 2:01am the day and night will be almost equal. That’s why it’s called the Spring or Vernal Equinox. Some years it falls on March 19th. It would occur on the same day every year if the Earth took exactly 365 days to make a complete revolution around the Sun. But it actually takes the Earth 365.25 days on average to go around the Sun once. Whatever the exact date and time it’s spring and with St. Patrick’s Day also in a few days I plan to add something green to my garden and tick off a few tasks on my to-do list.

There are endless shades of green in nature because color is dependent on light. Humans can see more shades of green than any other color. This is an evolutionary trait handed down from our ancestors who needed to differentiate the shades of green in order to know which plants to eat and which to avoid. Everywhere you look, it’s green- forest green, apple green, olive green, fern green, sage green, chartreuse green. Even all those showy flowering trees blooming now will soon be sporting bright green leaves.

I often get a request for green to be in the color palette of plants that go into a garden. There are green flowers that you can grow and of course, many shades of green foliage. The low wavelength of green promotes calm, relaxation and restfulness.

Diamond Heights ceanothus is a lovely groundcover and doesn’t require much irrigation.

One of my favorite groundcovers for sunny areas that looks beautiful as it fills in between other low water use plants is Diamond Heights ceanothus. Carpet an area with this dense, low mat of golden yellow and lime-green variegated foliage. It looks great year round. The pretty light blue spring flowers take second place to the leaves.

This is one of those versatile plants, performing just as well in dry soils and tough situations as it does in sheltered gardens with partial shade and rich soils. If you want a spectacular effect, plant it as a group. Each plant covers 3-5 ft. Because the foliage makes a cover that weeds seldom manage to penetrate, it’s a real maintenance saver. Use it on difficult sites such as banks as well as in garden beds and raised beds. It’s also a stunner as a container plant, the foliage spreading wide on all sides.

Leucadendron Safari Goldstrike

Another great greenish flowering shrub to try is Safari Goldstrike Conebush. This leucadendron is a vigorous compact grower to 6 feet tall and blooms during the winter and spring. Its bracts are excellent as a cut flower and foliage harvesting. They grow in full sun and have low water needs.

Some of my favorite plants that have green flowers or shades of green foliage are green hydrangeas, green hellebores, lime green coral bells, Lady’s mantle, Sum & Substance hosta, fatsia japonica, green gladiolas, Mediterranean spurge and Bell of Ireland, of course

Design trends

Long-Lived Survivors in the Garden

One of the earliest, easy-to-grow, spring blooming shrubs in our area.

Many, many years ago my landscape designer group was fortunate to get a private tour by the head gardener at Filoli Gardens. One of the takeaways from this informative afternoon was the plants that have survived there since the early 1900’s without any care. They are true survivors.
Growing in out of the way places in the over 600 acres of Filoli are plants that you see blooming around here right now.

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. Forsythias 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.

Recently while reviewing plant preferences with a client they mentioned that spirea has done very well in their poor draining soil. I haven’t thought about this workhorse plant in quite a while. They’re not “trending”, but they are good, love-lived, easy-to-grown beautiful shrubs that deserve a second look.

Spirea japonica is drought tolerant once established. Bunnies and deer don’t like them and they are not invasive in our area. Blooming for a very long time they attract pollinators and can control erosion. Several varieties are grown and available including the classic ‘Antony Waterer’. Other popular varieties include Double Play Gold, improved form of ‘Goldmound’ and ‘Goldflame’. The brighter yellow foliages covers a more compact shrub and it blooms profusely with hot pink flowers from early to late summer.

Another early flowering plants that is easy to grow in the shade is Clivia or Kaffir Lily. Buds are just starting to form on mine. Every year I look forward to their huge flower clusters that emerge between dark green, strappy leaves. Even in dark shade they will bloom and brighten the late winter/early spring garden although they would do fine in morning sun. If you have a north facing window you can grow them as houseplants. Clivias are hardy to several degrees below freezing. Clivia bloom best when crowded.