Category Archives: organic weed control

Early Summer Tips

hydrangeas2 3Some things in the garden need to be planned out in advance while others happen by chance. For instance, this year when our spring rains stopped dead in their tracks I gave up adding any more acidifier to my hydrangeas. You need to change the pH of the soil around hydrangeas well before they set buds. I like mother nature to water for me early in the season and she didn't cooperate.  As luck would have it, the flowers this year are majestic purple, mauve and magenta where before they were sky blue. Frankly, I'm thrilled with this years color palette. Hooray for serendipity.

Early summer is the right time, however, for many other garden activities that you don't want to leave to chance.

Many plants, both vegetable and ornamental, are bothered by aphids and other sucking insects as well as foliage and flower eating bugs
.   From cucumber beetles, flea beetles, stink bugs, weevils, curculios to borers , the list of trouble makers is endless. .  To help deter them mix up some pepper spray in your kitchen.  
    1 tablespoon hot pepper sauce or 1 teaspoon cayenne pepper
    6 cloves garlic, crushed
    1 quart warm tap water
Let stand I hour, strain and spray plants either in the morning or evening.

Apply the second fertilizer application for the year to your citrus and fruit trees. The last one should be immediately after harvest.  Apply the fertilizer to the soil around the drip line of the tree where feeder roots are located and scratch into the surface. Water in well. As with all fertilizers, make sure the trees are moist before you fertilize. Young trees in their first, second or third growing season should receive half the rate of established trees.

If your fruit trees are starting to produce too heavily, remove excess immature fruits.  Doing so allows remaining fruit more room to grow and prevents branches from breaking under the weight.  When apples, pears and stone fruits such as apricots, nectarines, peaches and plums reach 1/2' in diameter, pick some off, leaving the remaining fruits spaces 6-10" apart along the branch.  Later, to protect your ripening fruit, enclose the tree with bird netting,  hang strips of mylar flash tape near brach tips or substitute old CD's.

If you battle dandelions and don't want to use chemical weed killers around pets and children, get out the white vinegar from the cupboard. On a hot sunny day spray straight white vinegar directly on the weed. This method will kill whatever it touches so direct the spray carefully. If the dandelion is in the lawn, wait a week, pour some water on the dead spot to dilute any lasting effects of the vinegar. Then poke a bunch a holes and drop in some grass seed. Sprinkle a bit of fertilizer where the seed is planted and keep the area moist. In three weeks you won't remember where the dead spot was and the dandelion will be long gone.

Another garden to-do this month includes summer pruning of wisteria. To increase flowering next spring and keep these vines under control cut new growth back to within 6" of the main branch. If you want to extend the height or length of the vine, select some of the new streamer-like stems and tie them to a support in the direction you wish to train the plant.

To encourage continued bloom on annuals, perennials and shrubs, remove faded flowers before they start to form seeds.  Make sure you remove the entire flower head and the base where seeds form ( such as the bulbous part of dahlia, petunia or fuchsia flowers) and not just the petals.  Cut the stem down to where leaves start.  The season has just started and you'll be enjoying lots more flowers in the months to come if you deadhead regularly.  
    
Another maintenance tip is to shear spring blooming perennials to keep them full and compact.  Candytuft, phlox subulata, aubrieta and other low growing perennials benefit if you cut off spent bloom and an inch or two of growth.  Other perennials and shrubs that benefit from the same treatment to keep them compact are erysimum, lavender and Pink breath of heaven.

Also re-apply mulch if it's getting thin in spots. Check ties on trees to make sure they aren't cutting into the bark. Cultivate lightly around trees to discourage weeds and allow water to penetrate.

Don't be afraid to move a plant that is not working where its growing now. Make a note in your journal reminding yourself to transplant it sometime in the fall. Gardening is a dynamic and fluid process. Enjoy piecing  together pieces of the puzzle.
 

What to Do about Invasive Plants

bull_thistleWe can't control those pesky weed seeds that blow into our gardens and take hold. There are ways to keep them from taking over, however. But what about those invasive plants that are already in our gardens like ivy and vinca major? What's the best way to deal with them? Then there are plants we buy ourselves that can invade natural areas. Are there better plants to use that are just as attractive and useful? Here are some solutions to make your garden happy.

One invasive thug that can take over is bull thistle, a relative of the edible artichoke. The seeds of this vigorous exotic take hold in disturbed areas including your beautiful garden soil and if not controlled can become a solid mass of impenetrable thistles in just a few seasons. Bull thistle only reproduces by seed so removal of the flowering stalks at this time of year will prevent them from spreading. The flowering heads must be discarded in a plastic bag and destroyed to keep them from forming viable seed. Because this weed is biennial you also need to dig out the first year plants that have not formed stalks. You can also mow thistles close to the ground a couple of times before they form stalks to reduce the population over time.

As a landscape designer and consultant I'm often called upon for advice for an area covered with vinca major or ivy. Both of these invasive species are too successful for their own good, smothering native plants and harboring pests such as rats and snails. Vinca major also serves as a host to the bacteria that causes Pierce's disease in grapevines. For your information, vinca minor has not been found to be invasive in California so far

You can choose organic methods to control vinca and ivy rather than chemical herbicides. Hand vinca_majorremoval is labor intensive but the results are good if all the root nodes and stolons are removed. Work inward from the perimeter of the patch and pull the plants back. You will need to do this every 3 months during the first year to remove resprouts but native plants may recolonize the area and reduce the chance that other weeds will move into the area following the disturbance caused by the removal activities.

Replanting with another more desirable groundcover is another solution. For shady areas, try planting wild ginger  (Asarum caudatum), Catalina perfume ( Ribes viburnifolium), creeping snowberry ( Symphoricarpos mollis), yerba buena ( Satureja douglasii ), bear's foot hellebore (Helleborus foetidus), winter saxifrage (Bergenia cordifolia), pachysandra, Serbian bellflower (Campanula poscharskyana) or Asian jasmine.

Good substitutes for vinca or ivy in sunnier spots include groundcover types of manzanita and ceanothus. Also attractive are Taiwan raspberry (Rubus pentalobus), California fuchsia (Zauschneria), or beach strawberry (Fragraria chiloensis ).

Some plants even though purchased from a nursery can cause problems. You wouldn't buy a Scotch or French broom knowing how invasive they can be. Forsythia, Japanese kerria, golden currant and Jerusalem sage all provide that beautiful spring butter yellow color in the garden.

The licorice plant (Helichrysum petiolare) gained popularity for its deer resistance and foliage color many years ago. Unfortunately, it self sows wildly and the spreading branches will root at any point of contact with the ground. Try instead better behaved plants like California natives salvia leucophylla or eriogonum giganteum. Teucrium germander or Powis Castle artemisia also work well in the same area.

Another good plant gone wrong is cotonester  lacteus (parneyi).  The red fall berries are spread by cotoneaster_lacteus_Parneyibirds and with their rapid growth and competitive roots they can overtake the garden and wild areas. Fortunately there are many other plants to use instead that provide food for birds and are beautiful, too. Try planting toyon (Heteromeles arbutifolia) a California native with delicate white flowers and large clusters of brilliant red berries. Pineapple guava is another good substitute as is strawberry tree (Arbutus unedo).

These are just some of the suggested alternatives for invasive garden plants for this area. Don't give an invasive an inch, it can take over your garden, the neighbors and our wildlands.