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.

All Things Blue in the Garden

While harvesting blueberries at a friends’ garden I started thinking of the color blue and why it appeals to all of us gardeners. I was taking care of this fabulous garden while the owners were out of town so I had a lot of time to enjoy all of the plants including the blue flowering ones.

Blueberries-fresh off the bush- delicious

The color blue, especially in the summer, soothes our senses. Soft blues will calm the mind and aid concentration. Strong blues can stimulate clear thoughts. I’m not sure if the different blueberries fall into this category but I sure enjoyed tasting each of them.

Of the 4 different types of blueberries I harvested I think I liked O’Neal, a variety of Southern high bush, the best.
The large light blue early South Moon were also delicious as were the Blueray and Bluecrop. Although many blueberry species are considered self-fertile, all blueberry bushes benefit from cross-pollination and produce larger and more full flavored crops with another bush nearby. To ensure bees carry pollen from one bush to another, space them within 6 feet of each other.

The author’s hydrangea garden

When the weather gets hot I head to the part of my garden where the blue hydrangeas are blooming. I have several mophead types that vary in color from sky blue to deep blue. One is almost blue-violet this year although I didn’t add anything to the soil this winter to make it more acidic. I don’t have any lacecap varieties so I took a cutting of a spectacular Mariesii variegated one at the garden I was tending. It’s the white in both the foliage and the flower that makes the rest of the blue blossoms really standout.

True blue flowers are rare. We use words like cerulean, azure, cobalt, sapphire, turquoise, electric blue or steel blue when describing blue flowers. Hybridizers have tried for years to produce a true blue rose or blue daylily. Blue plant pigment is hard to manipulate. It occurs in the daylily as a sap-soluble pigment and is difficult to segregate. Lilacs, purples, orchids and mauves we have and working with them hybridizers may eventually get near blue, but pure blue probably never.

Rose hybridizers striving for true blue have come close by crossbreeding lavender hybrid teas in order to produce offspring having optimum amount of cyanidin, The results have been more of a silvery lilac or mauve. A blue rose is still in the future although labs in Australia and Japan are genetically modifying the pigments from petunias to produce a blue rose. Their results are not yet perfected and these roses are more of a lilac in color and can not survive conditions outside the lab. It is apparently very difficult to isolate the pigment cyanadin. Delphiniums have a monopoly on it.

There are many blue perennials as handsome as they are durable that we can enjoy in our gardens today.
Besides the old fashioned hydrangea, there are violas and campanulas. I”m also growing a blue impatien called ‘Blue Diamond’ that attracts the hummingbirds. All are valuable in the shade garden along with omphaloides and brunnera. The blue spikes of a long blooming peach-leaf campanula just go together with the white and green variegated foliage of Jack Frost Siberian bugloss.

In early spring we are dazzled by our native ceanothus which bloom with deep blue, sky blue or electric blue flowers. Emerald Blue phlox subulata carpets the ground in spring with clear blue flowers. Penstemon heterophyllus, a California native hybrid, carries dense spikes of bright blue, bell-shaped blossoms.

Make sure your garden has a blue section to cool you on a hot day.

Increase your Collection of Tall Bearded Iris

Last May I was fortunate to be able to spend the morning in Scotts Valley painting the tall bearded iris growing at Jim and Irene Cummins place. On their property they grow hundreds of varieties and if you are an aficionado of this regal flower you have a chance to add to your collection when the Monterey Bay Iris Society hosts their annual sale. Your first opportunity is at Deer Park in Aptos on August 4th from 9:00-noon and another sale takes place at Cabrillo Farmer’s Market on August 11th also from 9:00-noon.

Joe Ghio 2016 tall bearded iris hybrid

Jim and Irene welcomed my group of fellow artists sharing the history of their property and their growing tips. Amidst the beds of prized bearded iris is an impressive antique farming implement collection. This historic property dates back to 1849 when an older house was built as a stagecoach stop where a fresh team of horses could be changed out.

Jim told me that considering the history of the property he and Irene started displaying the old stuff they had and decided to add more by going to auctions and yard sales. Everywhere you look they have created an interesting vignette of plants and artifacts. Displayed on the old barn is an impressive vintage wrench collection as well as dozens of spigot handles. Antique tractor seats, watering cans, washing tubs, rusted bed frames, wagons, old kiddie cars- you name it, Jim and Irene have collected it.

Handmade birdhouses with vintage watering can collection

Due to the abundance of old wood on the property Jim said he started building Irene birdhouses. With so many interesting things to enjoy I had a hard time deciding what to paint. I took dozens of photos but settled on capturing their magnificent tall bearded iris in full bloom.

Jim is on the board of the Tall Bearded Iris Society (TBIS) and is also active in Historic Iris Preservation Society. As I walked around the blooming iris beds I noticed many had the name of Joe Ghio as their hybridizer. Some of the Cummins original rhizomes were collected from him as well as other iris gardens in the area. Early on they could only afford to buy a few of their older and less expensive offerings but as their garden began to grow they joined the Monterey Bay Iris Society.

The Cummins iris farm has been so successful that in 2019 when the National Convention is being hosted by Region 14 their garden will be one of the host gardens on the tour.

Antique wagon with old milk cans

When I asked Jim for the growing tips that make his iris so spectacular he told me he mostly uses lawn trimmings and tree leaves along with their native sand to break the soil down. “Iris don’t seem to care much as to soil type, they just need good drainage”, he said. He fertilizes with a balanced granular 15-15-15 fertilizer, using only an 1/8 cup or less sprinkled around each clump around Valentines Day and again in August or September. Another tip he told me was to be sure to plant the rhizomes real shallow with the tops showing and about 12-18 inches apart. They water every 2-3 weeks although he says they can go longer between irrigations.

At the upcoming sales, there will be a “How to Grow Iris” handout available as well as many member of the society available to answer question. At $4 each for these spectacular iris or 20 for $60 adding to or starting an iris collection may just be in your future.

Growing Lavender

Lavender, a member of the mint family, is found across Europe, the Mediterranean, north and eastern Africa, southwest Asia to southeast India and fits right into our similar environment. Everybody has their favorite type. Mine happens to be a compact English variety called Hidcote but there are hundreds available including a new, tough, variegated one called ‘Meerlo’. Here’s how to grow yours so it flourishes and doesn’t end up woody and spindly.

Lavender farm on Whidbey Island in Washington.

Lavender needs good drainage. Incorporate organic matter if necessary to make the soil loose and friable. Compost is the best amendment because it is fertile and the uneven particle sizes create better air spaces and give the roots better anchors to attach themselves to. Check the soil’s pH (potential hydrogen) to make sure it falls somewhere between 6.5 and 7.5. If the soil is too acidic the lavender will not thrive. If the soil is too alkaline, the nutrients are “tied” up in the soil and the plant cannot use them. Yellowed growth can be indicative of a soil that is out of balance. Adding compost can help to balance the pH.

Mulching with a fine mulch or compost after planting helps with the weed control. Avoid mulching right up to the stem of the small plant. Instead, leave a collar about two inches wide around the plant.

In the ground or in a pot, full sun is a must. In hot areas, some late afternoon shade can be tolerated without effecting flowering. Lavender in the field rarely needs fertilizer, especially if compost is applied as a mulch. More often, problems arise because the soil is not healthy. Avoid chemicals in pesticides, herbicides and fertilizers that kill or starve the beneficial organisms in the soil.

While Lavender is extremely drought resistant once established, they grows larger and produce more blooms with occasional deep watering depending on your soil type. This means that when the soil is dry several inches down, water thoroughly, then let it dry before soaking again. Often I see older foliage that has yellowed due to lack of moisture.

Lavender plants should be pruned every year immediately after bloom. Pruning should not be confused with harvesting. Pruning is necessary to extend the life of the plant. Cut back not only the flower stem, but also about a third of the gray-leaved stems as well. If the plant has been neglected, it can be cut back further, but avoid pruning back to only woody stems with no leaves showing. A plant pruned into the wood may push out latent (sleeping) buds or it may die.

It’s possible to have a lavender blooming in your garden most of the growing season. Here are my favorites.

Spanish lavender starts blooming early to mid spring. These do best with a good pruning about four or five weeks into the bloom cycle, which discourages these large bushes from becoming untidy and sometimes encourages a second sweep of blooms. Spanish lavender is sometimes referred to as French lavender since it grows wild in France.

French lavender has the more traditional gray leaves but with serrated edges. This large, fast growing shrub is sometimes referred to as everblooming lavender. French lavender does best when kept at no more than three feet, including blooms. Goodwin Creek lavender is a hybrid of French Lavender with a shorter growth habit and a darker purple flower head that is held on a longer wand. It makes a nice border or edging plant.

English lavender (Lavandula angustifolias), like Munstead and Hidcote start flowering in mid to late spring. They look great when they flower, and after pruning, remain a compact ball or hedge with exotically fragrant leaves the rest of the year. Hidcote is famous for its dark purple flower.

The English hybrids come in third in the bloom cycle and continue into mid summer. These are the workhorses of the lavenders. Provence and Grosso are the best known and are the ones to line the drive or border the garden.

Ceanothus: The Most Valuable Plant in your Garden

Those of you who read my column regularly might have noticed I often write about plants that are valuable to the birds and the bees as well as butterflies and wildlife in the general. I have 10 bird feeders around my house. Four for the hummingbirds and the other six have black oil sunflower seed and hulled chips. At this time of year when there are so many young the extra food is much appreciated. I provide water and nectar plants for the bees and butterflies as well. If I had to choose one plant to grow that would provide the most benefit for all the critters it would be ceanothus. Hands down, it’s the best and here are some of my favorite varieties.

Ceanothus ‘Carmel Creeper’
Ceanothus ‘Heart’s Desire’

The groundcover varieties I have in my landscape are Anchor Bay, Carmel Creeper, Heart’s Desire, Centennial and Diamond Heights. If deer frequent your landscape you should stick with Anchor Bay, Heart’s Desire and Centennial but the others are great in protected areas.

One of the upright types I grow is ceanothus thysiflorus. It’s one of the earliest native shrubs to bloom in our area. Ceanothus thyrsiflorus grow along a narrow band close to the coast from Monterey to southern Oregon. I also grow Julia Phelps with those electric blue flowers and Ray Hartman.

A new variety I’ve recently learned about from my friend and fellow Press Banner columnist, Colly Gruczelak, is called Celestial Blue. She planted several 2 years ago from 4″ mail order sleeves and they are now 3 ft tall and 4 ft wide. In her sandy garden, home to her personal deer population, the flowers look like blueberry sherbet. With a light fragrance, described as grape tart, it makes a good screen or accent. This cultivar is probably a hybrid of Julia Phelps and Concha. A horticultural cultivar is simply a plant variety that’s been selected specifically for gardens. Celestial Blue flowers 9 months a year especially in the summer when it explodes with rich purplish blue flowers.

A great variety I often use when designing a garden is Ceanothus ‘Concha’ because it will accept summer water more forgivingly than most and tolerates clay soil more than other species.

Joyce Coulter ceanothus also tolerates clay, summer irrigation and shearing better than other cultivars. It”s a good bloomer, drought tolerant and is covered in spring with wildly fragrant blue three-inch flower spikes.

Ceanothus is often said to be short lived. Most varieties need good drainage, little summer water and don’t need soil amendments. In their wild conditions ceanothus plants have a natural life cycle of 10-15 years although some live longer.

Diamond Heights ceanothus

Several members of the ceanothus family can form a symbiotic relationship with soil micro-organisms and fungi, forming root nodules which fix nitrogen. This is a reason why fertilizing is not normally recommended. Adding fertilizer mights kill off the good micro-organisms. Ceanothus are better left fending for themselves.

Ceanothus provide excellent habitat for birds and insects. They are good for attracting bee and fly pollinators and are the larval host plants for the beautiful ceanothus silkmoth. Ceanothus seed is readily eaten by many local birds. Planting a ceanothus is an important step to attracting more birds and wildlife to your garden.

Early California Indians used the fresh or dried flowers of some varieties for washing, lathered into a soap. it has been said to relieve poison oak, eczema and rash.

The Cutting Garden

Bringing flowers indoors, whether displayed in a simple mason jar or a crystal vase, brightens my day. I wish I had more flowers growing in my own landscape.

A mixed bouquet of fragrant roses and carnations with quince and gerbera daisies.

The secret to a fabulous bouquet is not just the flowers but the interesting foliage and that is something we all have in our gardens. I’m still going to plant more perennial flowers that are good for cutting but I’ll use them as accents in bouquets and concentrate on more foliage.

Great foliage plants come in all shapes and sizes. In shady gardens, fragrant variegated daphne odora is a wonderful small shrub for both flowers and foliage. Sweet olive or osmanthus fragrans is a large evergreen shrub with apricot scented blooms. Pittosporum ‘Marjorie Channon’ will add white with a hint of lime to your bouquets. Oakleaf hydrangea foliage and flowers look great in bouquets during the summer and the leaves turn red in fall as an added bonus. Our native shrub philadelphus, also called mock orange, has flowers that smell like oranges and will grow in some shade as well as sun.

For sunny spots grow penstemon and kangaroo paw. Coreopsis attract butterflies and are long lasting in bouquets.
Perennial coneflowers, dahlias, gloriosa daisy, delphinium, foxglove, scabiosa, aster, shasta daisy and yarrow also make good cut flowers. Self-sowing annuals that have a long vase life are bachelor buttons, clarkia, cosmos, flax, love-in-a-mist, nasturtium, cleome and calendula.

A deconstructed bouquet of peonies.

Native flowers that last for a week or more include clarkia and sticky monkeyflower. Yarrow and hummingbird sage will last 4-6 days.

To make cut flowers last, pick them early in the morning before heat stresses them. Flowers cut in the middle of the day will have difficulty absorbing enough water. Cut non-woody stems on a slant for maximum water absorption. Woody stems can be cut straight across but smash the ends. Plunge immediately in a bucket of tepid water. Indoors, fill a container with cool water and re-cut each stem under water so an air bubble doesn’t keep water from being absorbed.

Pull off any foliage or flowers that will be below the water level in the vase. Fill a clean vase with 3 parts lukewarm water mixed with 1 part lemon-lime soda, 1 teaspoon vinegar and a crushed aspirin. Another recipe for floral food is 2 teaspoons sugar, 2 tablespoons white vinegar and 1/2 teaspoon bleach in 1 quart water. The sugar helps buds open and last longer, the acid improves water flow in the stems and the bleach reduces the growth of bacteria and fungus. Change the water and re-cut the stems every few days to enjoy your bouquet for a week or even longer.

While just about any plant material that strikes your fancy will work in a mixed bouquet there are four types of plant forms that naturally look good together: Spires for height and architectural properties with flowers like liatris, snapdragon, gladiola, salvia, Bells-of-Ireland as well as the strappy leaves of flax or cordyline. Round flowers such as roses, dahlias, long-stemmed marigolds and peonies provide focus. Lacy flowers are fillers- ferns, baby’s breath, dill. Foliage from shrubs such as abelia, breath of heaven, California. bay, ornamental grasses, grapes and other vines, herbs, woody tree branches like smoke tree and Japanese maple which also look handsome in a bouquet.

A deconstructed arrangement separates each type of flower into their own vase or container instead of grouping them in a mixed bouquet. Vary the size and shape of the vases and containers and group them together to create a unique vignette. All bouquets are beautiful.

Harvesting, Drying and Preserving Herbs

Now that you have an assortment of herbs growing nicely in your garden what do you do with them? Mine seem to be growing more exuberantly than I anticipated and if I don’t keep up with snipping them often some will go to seed or get leggy and unproductive. Then what would I do when I’m putting together my favorite nectarine-caprese salad with fresh basil and mint leaves?

Chives and Tuscan Blue rosemary

Most herbs should be harvested before the plants are about to bloom when leaves are at peak flavor and oils are strongest. Fresh leaves may be picked as soon as the plant has enough foliage to maintain growth. Harvest on a sunny morning after the dew has evaporated. To fully harvest annual herbs such as basil cut all stems back to just above the bottom two sets of leaves. Perennial herbs like sage should be cut back to about a third of their height just above a set of leaves. As you collect your harvest, keep them out of the sun or they will quickly wilt.

To store, wash herbs lightly with the leaves on the stems in cold running water to remove soil, dust or bugs, Drain on absorbent towels or hang plants upside down until the water evaporates. Then hang to dry thoroughly in small bunches in a dark, warm, well ventilated room. You can also lay them in a shallow basket or on a screen. if drying on a screen or basket remove large-leaved herbs from the stems before spreading them out. Smaller leaved herbs like thyme, savory or rosemary can be left on the stem to dry.

Herbs with a high moisture content, such as mint and basil, need rapid drying or they will mold. To retain some green leaf coloring, dry in the dark or by hanging plants upside down in bunches in paper bags.

Those herbs with a high water content like tarragon, basil, chives, lemon balm, mint and dill freeze well. Frozen herbs will keep their flavor for several months. Unlike dried herbs whose flavor is more concentrated when dried, frozen herbs can be used in the same proportion as fresh.

Herbs are dry when they crackle and crumble when rubbed between your fingers. Strip them from the stem and pack in labeled jars as they tend to look alike when dried. Crushing the leaves releases their essential oils so don’t do that until you use them.

Here are some herbs that do double duty in the garden:
Basil- repels flies and mosquitos. Plant with tomatoes to improve flavor.
Catnip- deters flea beetles, aphids, squash bugs, ants and weevils. Also repels mice.
Chamomile-improves the flavor of cabbages, onions and cucumbers. Accumulates calcium, sulphur and potassium, returning them later to the soil. Also a host for beneficial hoverflies and good wasps and increases the productions of essential oils in herbs.
Chives- improves growth and flavor of carrots and tomatoes. Keeps aphids away from mums and sunflowers. When planted by roses, helps prevent black spot.
Coriander/cilantro- repels aphids, spider mites and potato beetle. Coriander tea is a good spray for spider mites.
Dill- improves the growth and health of cabbage and lettuce. Plant by tomatoes to trap the tomato hornworm. Attracts many beneficials. Do not plant by caraway or carrots.
Lemon balm- deters many bugs, especially mosquitos and squash bugs.
Mint- deters cabbage moths, ants, rodents, aphids and fleas. Attracts hoverflies and predatory wasps. Attractive to earthworms.
Rosemary- plant with cabbage, carrots, beans, and sage, Deters cabbage looper and bean beetles.
Tarragon- beneficial to plants throughout the garden as is thyme.