Category Archives: perennials

Hardy Geraniums in the Garden

Geranium ‘Orion’

I feel sorry for them. They are the wallflowers of the nursery. Shoppers barely glancing their way before moving on to attention getters like dinner-plate dahlias. In the garden, though, they shine. They are the work horses of the perennial border. I’m talking about true geraniums- those hardy, versatile, long blooming plants for edgings, borders and ground covers.

Most people use the common name geranium to describe what is actually a pelargonium. Ivy geraniums, Martha Washington pelargoniums and zonal geraniums are all pelargoniums. Hardy geraniums, also called cranesbill, look very different. Leaves are roundish or kidney-shaped and usually lobed or deeply cut. Flower colors include beautiful blue, purple, magenta, pink or white and often completely cover the plant with color. I’ll bet if you visited a garden on a tour or admired a picture in a garden magazine it contained true geraniums. Here are just a few strong performers available among the dozens of species.

Geranium ‘Maderense’

Geranium maderense grows best in shade. This dramatic native of Madeira is the largest geranium with huge 1-2 foot long leaves shaped like giant snowflakes. Clusters of thousands of rose tinted flowers form on a 3 foot trunk. This perennial is short-lived but self sows freely. Add some of these architectural plants to your border for color and structure.

Blue flowers in the garden are always a hit as they combine so well with other colors. Geranium Orion’s abundant clear blue flower clusters bloom over a long season. Use this 2 foot spreading plant in sun or part shade in a mixed border or as a groundcover. There are other blue flowering geraniums. I grow geranium ‘Brookside’ on my own garden. It’s on it’s second round of blooms. It’s large bright blue flowers are larger than ‘Johnson’s Blue’. ‘Rozanne’ is another common favorite with stunning blue flowers.

Another fast growing variety is geranium incanum which covers itself spring through fall with rosy violet flowers. Cut back every 2-3 years to keep neat. This variety endures heat and drought better than other types but needs some summer water. It self seed profusely which might be exactly what you want as a groundcover in a problem area.

Geranium ‘Biokovo’

If pale pink is your color, plant geranium x cantabrigiense ’Biokova’. This excellent groundcover spreads slowly. The numerous one inch flowers are long lasting and cover the plant from late spring to early summer. Their soft pink color is indispensable when tying together stronger colors in the border and the lacy foliage is slightly scented.

Gernaium ‘Karmina’

Another geranium in the same family is ‘Karmina’. I’ve been growing this dark pink flowering variety for several years. With lush green leaves on a low spreading plant it’s pretty even when not in bloom.

There are a couple other varieties that are popular and deserve a try. They are Award Winning Mavis Simpson’ and Russell Pritchard’. Both have bright pink or purple flowers and make good additions to your perennials.

Give a hardy geranium a place in your garden.

Make Every Drop Count:Best Watering Practices

Low water-use leucospermum or Pincushion.

Water is our most precious resource. One of the Apollo 11 astronauts recently said that the look back from the moon at our planet and blue oceans to be even more impressive than the moon itself. Life can’t exist without water. You are the steward of your own piece of planet earth. How you water can make it thrive and you can save water at the same time.

With summer water bills arriving this is a good time to re-visit how often and how much to water that landscape you’ve spent so much money to create. Basically, you’re wasting water if you water too shallow or too often. Here are some guidelines.

Photosynthesis is one of the most remarkable biochemical processes on earth and allows plants to use sunlight to make food from water and carbon dioxide. At temperatures about 104 degrees, however, the enzymes that carry out photosynthesis lose their shape and functionality. A garden that provides optimum light and water but gets too hot will be less vigorous.

California native Fremontodendron

Plants have natural systems that respond to heat problems. Plants can cool themselves by pumping water out through the leaves for a kind of swamp cooler effect. They can also make “heat-shock” proteins which reduces problems from over heating. All these strategies can take resources away from a plant’s other needs like growth, flowering and fruiting.

So how much water do different types of plants need during the heat of summer?

Be sure that you water trees and shrubs deeply checking soil moisture first with a trowel. Established small to medium shrubs should be watered when the top 3-6″ is dry, large shrubs and trees when the top 6-12″ is dry.

As a rule of thumb, trees and large shrubs need deep but infrequent watering. They should be on a separate valve than your smaller shrubs and perennials. Water ornamental trees 1-3 times per month depending on the type and soil. Tree roots grow 12-36” deep and require 10 gallons of water per inch of trunk diameter.

Apply water with a soaker hose, drip system emitters or hand held hose with shut off and soft spray attachment according to your water district’s restrictions. Don’t dig holes in the ground in an effort to water deeply. This dries out roots even more. Be sure to water the root zone to the indicated root depth every time you water. Watering deeper than the root zone only means you are wasting water. You can test how deep you watered by pushing a thin, smooth rod into the ground soon after you irrigate. The soil probe should easily slide through the wet soil but become difficult to push when reaching dry soil.

The roots of smaller shrubs are 12-24” deep in the soil. Established native shrubs may need only monthly waterings to keep them looking their best while other shrubs may need watering every 7-10 days during the heat of the summer. Perennial roots only go down 12” or so and may need watering once or twice a week depending on type.

grevillea lanigera ‘Mt. Tamboritha’ groundcover

When is the best time to water? Watering in the morning is the most efficient whether you water by sprinkler, drip system, soaker hose or by hand. The water soaks deep in the soil without risk of evaporation. It bolsters the plant for the day and has dried from leaves by evening reducing the risk for foliar diseases like mildew. Plant roots are also more receptive to watering in the morning.

Is it true that water droplets will scorch leaves in the midday sun? According to a study, fuzzy-leaved plants hold water droplets above the leaf surface and act as a magnifying glass to the light beaming through them so there is a very slight chance of scorch. The study also reported that water droplets on smooth leaves, such as maples, cannot cause leaf burn, regardless of the time of day.

February in the Garden

I’m waiting patiently for the buds on my pink flowering currant to start lengthening a bit more. I wasn’t counting on the recent snow and cold snap but the buds are showing color and are doing fine. Although still small at this stage I’ve assured my hummingbird population that they’re on their way. When I was out pruning last week I didn’t touch this plant otherwise I’d have cut off all those potential flower clusters loaded with nectar. This is what I did do in my garden.

To stimulate new growth I trimmed woody evergreen shrubs like abelia and loropetalum. The Mexican bush sage and artemisia were cut to within a few inches of the ground. I don’t use this approach on lavender or ceanothus, though. Lightly prune those after blooming later in the season and don’t cut back to bare wood inside the plant.

Between rain storms I’ll prune my fuchsias back by a third and remove dead, crossing branches and interior twiggy growth. The hanging fuchsias will be cut back to the pot rim. Fuchsias bloom on new wood so even if your plants didn’t lose all their leaves cut them back.

I cut back all the hydrangeas stems that bloomed last year and will apply a soil acidifier soon as I want the flowers as blue as I can get. Although aluminum sulfate is the traditional favorite for quickly acidifying soil it’s not as kind to beneficial soil microorganisms. Coffee grounds, pine needles, peat moss and cottonseed meal are better for your soil.

Don’t prune spring flowering shrubs like lilac, weigela and spirea or flowering trees such as cherry, plum and crabapple now. These and plants with buds like rhododendron, azalea and camellia should be pruned after they flower. You can cut some branches while they are blooming to bring into the house for bouquets.

Even if you have already pruned your roses be sure to remove old leaves still clinging to the plant. Those will most likely develop fungal spots and diseases later if you don’t. Rake up any debris beneath the plant and discard to eliminate overwintering fungus spores

Roses are super forgiving and you can trim them up again using the following guidelines. The goal is to produce lots of roses not just a few of exhibition size. Aim for a vase-shaped bush with an open center.

Prune old garden roses that bloom once in the spring after flowering. Climbing roses require little pruning. Cut out extra stems if there are too many and also cut back long established canes to about the place where they are slightly thicker than a pencil. Then cut each side stem down to several inches. This will cause the cane to flower along its complete length for a beautiful spring display.

Wait to prune back perennials that may have their new foliage damaged in a late frost. Same goes for shrubs that might have gotten hit by frost. That damaged foliage can protect the plant from further frost damage. Mid-March is the estimated date of hard frost in our area or at least it used to be. We gardeners are always betting Mother Nature will go our way and our efforts will not have gone in vain.

Prune fruit, nut, shade trees and deciduous vines like clematis.

Cut back ornamental grasses if you live where you rarely get frost. I’m pruning California fuchsia, salvia ‘Bee’s Bliss’ and hummingbird sage now. They look okay but I want the encourage new, compact growth.

And now I’m making myself a cup of tea and watching the chipmunk action in my garden. All of nature is getting ready for spring.

Fall Tasks in the Garden

Some people wait all year for fall weather to arrive. The heat of summer is over and the tourists are gone along with that pesky fog along the coast. For us up here in the Santa Cruz mountains, this is one of the best times to be outside. Here are tips for early fall in the garden.

Late fall is not a good time for major pruning so if you have some shrubs that need a tune-up do it soon.  Wounds heal slowly later in the fall, leaving them more susceptible to disease. As a general rule, don’t prune when leaves are falling or forming. Wait to prune most trees until late in the dormant season or in late spring after leaves and needles form. To avoid sap flow on birches and maples, prune after leaves mature. Fruit tree summer pruning should have already been done when growth ceased.

Refresh perennials, such as butterfly bush, salvia and yarrow by cutting a third to half of their growth later in the fall.

Rake leaves- compost or put in your green can. If large leaves are left in place they will mat down and set up fungal problems come spring.

Remove dead and diseased leaves from under camellias, rhododendrons and roses.

 

Bearded iris

Now through October, divide summer blooming perennials that are overgrown and not flowering well. Alstroemeria, agapanthus, coreopsis, iris, daylily, yarrow, rudbeckia, calla lily, aster and penstemon fall into this category. You can also divide spring blooming perennials like candytuft, columbine, astilbe, bergenia and bleeding heart although they don’t always bloom the first spring afterwards due to the energy they use re-establishing themselves. If you’re on a roll out in the garden, though, go for it now. You never know what other projects you may be working on next spring.

Start perennial flowers seeds now so that they will be mature enough to bloom next year.

Fertilize shrubs lightly one last time with an all-purpose organic fertilizer or layer of compost. Use compost only on California natives.

broccoli with sweet alyssum

Plant cool season veggie starts like broccoli, cabbage, cauliflower, chard, lettuce, spinach, brussels sprouts, onions and leeks in soil enriched with 4-6″ of compost as summer vegetable crops will have used up much of your soil’s nutrients.You can sow seeds of beets, carrots, radishes, spinach, arugula, mustard and peas directly in the ground. Planting early ensures your plants get a good start before cold weather sets in and growth mostly stops until spring. You’ll be able to start harvesting in just a couple months if you start now that the weather has started to cool.

If you aren’t going to grow vegetables in the garden this fall consider planting a cover crop like bell beans, fava beans and vetch after you’ve harvested your summer vegetables. Next month I’ll talk about how to go about doing this and how this benefits your soil.

Cut back berry vines that have produced fruit. Canes of the current season should be trained in their place.

Spider mites and thrips are especially prolific during the late summer. If some of the leaves on your plants are pale with stippling, spray the undersides of infected leaves with organics like insecticidal soap switching off with neem oil as they build up a resistance to one of the pesticides. Plan to spray with a horticultural oil in the winter to kill overwintering eggs.

The Dog Days of Summer

They’re called the Dog Days of summer. You know those sultry days with the hottest summer temperatures. The Romans associated the hot weather between July 24th and August 24th with the star Sirius which they considered to be the “Dog Star” because it’s the brightest star in the constellation Canis Major (Large Dog). The Old Farmer’s Almanac uses slightly different dates but the Dog Days of summer are definitely here.

Dahlia- a repeat bloomer

Recently I moved to Bonny Doon where gardening in the hot, sandy soil is very different than the shady clay I was used to. One thing I’ve noticed is the existing drip system has not been modified to allow for the growth of the plants. The emitters which were originally placed at the base of each plant are not even close to covering the current size of the root zone. The crown of the plant is getting overwatered with each cycle but the rest of the plant is bone dry. Time to add more emitters maybe even downsizing to half gallon ones and moving them away from the middle of the plant. No sense wasting water that’s not doing the plant much good.

As summer rolls along you may become more aware of the different microclimates in your garden. With the drier and hotter weather this year some of your plants that used to get along just fine might be showing signs of stress. Taking note of these changes in the performance of your plants is what makes for a more successful landscape. When the weather cools towards the end of September you will want to move or eliminate those plants that aren’t thriving. Be sure to keep a thick layer of mulch on the soil around your plants to conserve that precious water you do allocate to each of your irrigation zones.

Roses with Baby’s Breath- deadhead regularly

The dog days of summer may be affecting our garden but it doesn’t have to stop us from being out in the garden. . The joy of gardening can take many forms including adding a wind chime, bird feeder or bird bath. Groom plants that need some cleanup. Many perennials benefit from a little haircut at this time of year to extend their blooming into the fall season. Santa Barbara daisies fall into this category. Lavenders will keep their compact shape by pruning a third of their branches now. This forces new growth in the center so the plant doesn’t get woody.

Deadhead flowering annuals and perennials as often as you can. Annuals like marigolds, petunias, zinnia and cosmos will stop blooming if you allow them to go to seed. The same is true of repeat blooming perennials like dahlia, scabiosa and lantana.

These plants know they’re on this earth to reproduce. If they get a chance to set seed, the show’s over- they’ve raised their family. Try to remove fading flowers regularly and you’ll be amply rewarded.

Strike it Rich rose

Fertilize shrubs lightly one last time in August or early September. All shrubs, especially broad-leaved evergreens such as rhododendron, pieris, camellia and lilac need to calm down, stop growing and harden off to get ready for the winter cold. Some plants have already set next year’s buds.

Roses will appreciate a bit of fertilizer now, encouraging them to bloom another round in September and October. To keep them blooming make a habit of pinching and pruning off old flowers. Always cut back to an outward facing branch-let with five leaves. There are hormones there that will cause a new rose to grow much sooner than if you cut to one with only three leaves.

Post Thanksgiving What-Not-To-Do List

Twas the weekend after Thanksgiving and all through the house, not a creature was stirring not even a gardener. I should probably do something productive, but what? Should I be good and do a little light weeding? Maybe I can muster up the energy to plant a few more bulbs. Come spring I’ll be happy I did. Then again I could make notes of my gardening successes and not so great horticultural decisions. “I know”, I say to myself, “this weekend I’ll revel in what I don’t have to do in the garden”.

Japanese maple in fall color

I don’t need to prune trees and shrubs at this time of year. Other than clipping a few well placed branches to use in a holiday wreath, I’m off the hook for this task right now. Deciduous trees are still in the process of losing their leaves and are not fully dormant. Evergreens shrubs and conifers can be trimmed lightly but most shaping is done when they start growing in late winter or very early spring.

The season is pretty much over for me except to enjoy what’s left of fall color and the ornamental grasses waving their seed heads in the wind. A lot of perennials are dying back but I’m not in a hurry to neaten things up. The seed heads left in the garden supply food for birds and other creatures while the foliage provides shelter for the plant in the cold and frost. Remove anything that has turned slimy or just plain unattractive but leave berries and seed heads for food and winter interest.

Purple finch

At this time of year my garden is visited mostly by chickadees, nuthatches, goldfinches, purple finches and warblers. They will spend the winter here and I’m doing them a big favor by not cutting back brown foliage containing nutrient-rich seed heads. Some of the reliable seed producers that I won’t have to clean up this weekend include artemisia, aster, coreopsis, penstemon, sedum, lupine, salvia, black-eye Susan, coneflower, phlomis, monarda, agapanthus and grasses.

Chickadees gather hundreds of seeds in fall and early winter and store them in hiding places to ensure themselves a food supply later in the season. They are a remarkable bird that we take for granted being so common. I read in Audubon magazine a couple years ago that a chickadee weighs about as much as a dozen paperclips but their body is large for their weight. This means they have to ramp up the number of hours they devote to feeding. At night chickadees cram themselves into tiny cavities and shiver, burning the day’s fuel to keep from freezing.

Anna’s hummingbirds at feeder

Hummingbirds still need a nectar source at this time of year. Anna’s hummingbirds live in this area all year long. So In addition to the plants in my garden that supply nectar I keep my feeders up year-round and keep them clean. They need your nectar even more in the winter when very little is in bloom. In addition to nectar rich natives like mahonia my abutilons are a winter favorite for them.

Other tasks I can put off at least for this weekend include planting wildflower seeds. I see California poppies coming up all over the place. Nature knows when the time is right. Well, maybe I’ll broadcast a few working them into the soil very lightly. I need to hoe off some early weeds that would compete with them. How many calories are burned in light gardening tasks? I might just reconsider not being a total couch potato this weekend.