What to Do in the Garden in September

Abutilon bloom nearly year round and are relished by hummingbirds.

Summer is winding down. Already. Seems it barely started two months ago. Who doesn’t love these long days and warm nights? The calendar might say fall is near but Indian summer is one of the our best seasons so I love this time of year, too. But then I get all excited when spring rolls around and everything is in bloom. It’s all good. I have a check list of some garden tasks I need to do at this time of year so I better get to them between hiking and trips to the beach.

Fertilize shrubs lightly one last time if you haven’t already done so last month. All shrubs, especially broad-leaved evergreens such as rhododendron, pieris, camellia, hebe, 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 especially appreciate a bit of fertilizer now, encouraging them to bloom another round in October. To keep them blooming make a habit of pinching and pruning off old flowers. Always cut back to an outward facing branchlet 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. You can always cut lower on the stem if you need to control height.

Deadhead flowering annuals and perennials in the ground as often as you possibly can. Annuals like zinnias and cosmos will stop blooming if you allow them to go to seed. The same is true of repeat blooming perennials like dahlia, scabiosa, echinacea and lantana. Santa Barbara daisies will bloom late into winter if cut back now.

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. If you want to start perennial flowers from seeds this is the time so that they’ll be mature enough to bloom next year.

Now through October, divide summer blooming perennials like agapanthus, coreopsis, daylilies and penstemons that are overgrown and not flowering well. You can also divide spring blooming perennials like candytuft, columbine, astilbe, bergenia and bleeding heart but sometimes they don’t 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.

It’s still a little hot to plant cool season veggies starts in the ground. They appreciate conditions later in September when the soil is still warm but temps have cooled. It is OK to plant seeds of beets, carrots, spinach, arugula, mustard, leeks, onions, peas, radishes and turnips.

If you aren’t going to grow vegetables in the garden this fall consider planting a cover crop like crimson clover 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 are especially prolific during hot, dry weather. Sometimes you don’t even know how bad the infestation is until all your leaves are pale with stippling. Periodically rinse dust and dirt off leaves with water. Spray the undersides of infected leaves with organics like insecticidal soap switching to neem oil if they build up a resistance to one of the pesticides.

Now that you’ve taken care of your chores reward yourself by adding perennials to your garden for color in late summer through fall. Take a look at the garden areas that aren’t working for you and replant. Good choices include aster, chrysanthemum, coreopsis, and gaillardia. Abutilon also called Flowering Maple come in so many colors that you probably need another one in your garden. Petite Pink gaura looks fabulous planted near the burgundy foliage of a loropetalum. Don’t overlook the color of other foliage plants like Orange Libertia and Japanese bloodgrass in the garden.

One last to do: Make a journal entry celebrating the best things about your garden this year.

The Best Cut Flowers from the Garden

This mixed bouquet features late summer bloomer like verbena bonariensis,
rudbeckia, yarrow and cosmos.

Several of my friends have big gardens. Gardens that are big enough to have lots of blooming flowers that can be cut and barely make a dent in the riot of color in their garden. The other day I recieved a huge mixed bouquet. It’s spectacular. If you’ve always wanted a garden like this here are some tips for the best perennials and annuals to grow for cutting.

Don’t have much space to devote to a cutting garden? No problem. Although we all dream of a dedicated spot in the garden set aside for growing masses of flowers and foliage for bouquets, it’s not a necessity. Many great plants for cutting can just as easily be grown in raised beds, containers and between shrubs. So whether you prefer formal floral bouquets or casual, deconstructed flower and foliage arrangements let your imagination run wild and grow plants that make either easy to put together.

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. First are the spires for height and architectural properties. Flowers like liatris, snapdragon, gladiola, salvia, Bells-of-Ireland as well as the strappy leaves of New Zealand flax or cordyline fall into this category. Secondly are plants and foliage with a round form for focus such as roses, dahlias, long-stemmed marigolds and peonies. Last are the lacy accents for fillers- ferns, baby’s breath, dill and foliage from shrubs such as abelia, breath of heaven, smoke bush, Japanese maple and ornamental grasses. Grapes and other vines and herbs are also good as accents.

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.

In shady gardens, fragrant daphne odora is a wonderful small shrub that provides interesting variegated foliage as well as flowers. Sweet olive or osmanthus fragrans blooms smell like apricots. Oakleaf hydrangea foliage and flowers look great in bouquets and the leaves turn red in fall which is 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. Pittosporum ‘Marjorie Channon’ will add white with a hint of lime to your bouquets.

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 are good as 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. Annual flowers such as zinnia, lisianthus, snapdragon, statice and marigolds are great in containers where you can make every drop of water count and are also good for cutting.

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 recut each stem under water so an air bubble doesn’t keep the 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 recut the stems every few days to enjoy you bouquets for a week or maybe even two.