Powdery Mildew

A fungal disease which is found throughout North America, powdery mildew is easily recognizable by its white or greyish, talcum powder-like circles appearing on leaves, flowers and fruits of various vegetables, fruits, perennials and shrubs. The list includes roses, lilacs, dahlias, begonias, delphiniums, phlox, monarda (bee balm), euphorbias (spurge), catalpa (bean tree), zinnias…as well as squash, cucumbers, beans, peas, melons, apples, pears, strawberries, gooseberries, and grapes.

Zucchini ‘Dark Star’ with powdery mildew

Leaves covered by powdery mildew cannot manufacture enough food which can impact on plant growth and fruit development, depending on the rate of infection. But rarely does the mildew kill the plant. It just looks horrible.

There are a number of different fungi species responsible for powdery mildew. Some are species specific, others will attack a wider range of plant varieties. In regions of high humidity and moderate temperatures, the fungi produce mycelium and spores on the surface of affected foliage. The spores are then carried by wind currents to other plants.

Strangely enough, it is the wind which will reduce the risk of fungal infection. Providing adequate spacing between plants will increase air circulation and decrease the moisture retention on the leaves. Opening up shaded areas to more sunlight will also help.

Autumn is another trying time of year for protecting our plants and crops from powdery mildew. A lot of fungi spores repose in the soil and come fall, the rains splashing up onto the plants will often carry a few spores with the droplets.

No matter the time of year, once a plant has been infected, the mycelium will continue to spread on the leaf surface regardless of the moisture conditions.

And there is no known cure for powdery mildew…only prevention and a modicum of control once it appears. Best line of defence is to remove the affected leaves as soon as you spot them. Always put the infected plant parts in the garbage. Never put them in the compost unless you have a very hot pile.

To prevent powdery mildew on susceptible plants, mix up either of the following recipes. Both are reasonably effective.

Recipe #1:

One part cow’s milk
Nine parts water

Combine ingredients in a sprayer, if you have a lot of plants to treat…or a spray bottle if treating just one or two. Will have to be repeated after each rainfall.

 

Recipe #2:

1 gal water
1 tbsp baking soda
1 tbsp vegetable oil
1 tbsp dish soap

Combine all ingredients, in order as listed, in a sprayer or spray bottle. Preferably apply this mixture on cloudy days with no threat of rain. Applying on sunny days risks sunburn on the leaves.

Will protect the plant longer because of the addition of vegetable oil and soap in this recipe. However, it must be reapplied after a few rainfalls, or an especially hard downpour.

 

Submitted by Leslie Cox
CVHS member and writer as the “Duchess of Dirt”

How to Freeze Fresh Basil Leaves

Remove basil leaves from stems. Immerse them in a cool water bath and swish to remove debris and any bugs that may have hitch-hiked inside.

Fill your salad spinner with washed leaves and gently spin dry. (Doing this in smaller batches will help to remove the water droplets better.) Lay leaves out on clean, dry towels to finish drying. You can speed this up by gently patting the leaves with another clean, dry towel.

Once leaves are completely dry, fill a small or medium freezer bag about three quarters full. (A non-zip freezer bag works best for this.)

Gather up the neck of the bag tightly in the circle between thumb and forefinger. With finger from other hand, make a small opening in the neck of the bag. Blow air into the bag until it is fully extended to its limits. Quickly squeeze the neck of the bag shut to trap the air inside, and tie the bag shut securely with a twist tie.

Label the bag with the date, and type of basil species if you prefer. Place in the freezer.

Note: Be sure to keep all of your frozen basil at the top of your chest freezer. Piling anything on top of them risks expulsion of air from the bags, thus damaging your basil supply.

Frozen basil leaves will keep for a year, or more…but best to use up this year’s supply and replenish your stock with fresh leaves you freeze for the following winter’s use. (But good to know it will keep, just in case you do have a crop failure next year. Heaven forbid!)

Oh…and when you go to use your frozen basil leaves…open the bag and remove the amount needed for your recipe. Immediately, blow air into the bag following the method noted above, and secure the bag shut once again. Place the bag back in the freezer right away before the remaining leaves thaw.

 

Article submitted by Leslie Cox
CVHS member and writer as the “Duchess of Dirt”

Dealing with Green Tomatoes

October and it is high time all those tomatoes were picked off the vines in the greenhouse, regardless if they are still green. Tomatoes need a constant overnight temperature of 15.5 °C for proper growth and ripening. Lower temps sustained for longer than a week will cause growth problems, such as splitting, and delay ripening.

Green tomatoes can still be rescued and ripened indoors for fresh eating through the winter. One of the best methods is to place them in a single layer in newspaper-lined beer flats and cover them with a couple of layers of newspaper to keep them in the dark. (Tomatoes can be stacked two to three layers high if you are using deeper boxes, as long as you keep the heavier tomatoes on the bottom, and cover each layer with newspaper. However, for ease of regular checking for ripe tomatoes, the beer flats really work much better. And they stack wonderfully if you place each flat crosswise to the previous flat.)

Place the flats of green tomatoes in an unheated basement, or somewhere where it is relatively cool. Some people use their 2nd fridge but the tomatoes should really be kept at a slightly warmer temp than 4 °C.

Be sure to check through all of the flats on a weekly basis for ripened fruits. Such a treat in the middle of winter. So full of flavour.

 

Article submitted by Leslie Cox
CVHS member and writer as the “Duchess of Dirt” 

October Garden Chores

A list of chores to do this month:

  • It’s apple season! Store your harvest at 0 °C to 7 °C (32 °F to 45 °F). Some varieties will keep longer than others, so regularly check they are not spoiling.
  • Make sure to dry your beans well before storing in a moisture-proof, airtight container for making those soups and chili dishes over the winter.
  • Make sure your onions are dry and wiped clean of all dirt. Store away from apples and potatoes where it is cool and dry. Again, some varieties are better keepers than others.
  • Root Crops. Clean your potatoes, carrots, beets, etc. of any soil. Store in a cool, dark place. If you clip the tops off of your carrots, beets, parsnips, etc., they will stay fresher longer. (Some people like to store their root crops in sand-filled tubs.)
  • Squash and pumpkins should be washed with a 10 % bleach solution and wiped dry thoroughly for storing. They should be stored at 10 °C to 15 °C (50 °F to 65 °F).
  • Time to dig up the tender plants for storing, such as dahlias, canna lilies, begonia tubers, etc.
  • Right time to plant the spring-flowering bulbs, if you did not get this done last month. Put markers of some sort where you have planted your bulbs and late-flowering perennials. That way you will not dig them up in your spring enthusiasm.
  • Still time to divide and move those overgrown perennials.
  • Get on with the Fall clean-up schedule in the garden. Cut back those herbaceous perennials which are dying back, such as hostas. Put any plant debris which is showing signs of serious disease such as botrytis in the garbage, or on the burn pile.
  • Those piles of falling leaves. They are a wonderful, protective mulch for any borderline hardy perennials you may have snuck into your landscape design. Leaves are also great for protecting soil erosion from winter rains.
  • Good time to start some Paperwhite bulbs indoors now.
  • If you have kept last year’s poinsettia, and stored it in a dark closet, now is the time to bring it out into the light so it will produce those lovely, colourful bracts at Christmas.
  • Check your climbing roses are securely tied to their trellis so as not to risk any broken branches during the winter storms.
  • Put your garden furniture under cover to ensure longer life.
  • And for goodness sakes! Plant that garlic now!

 

Article submitted by Leslie Cox
CVHS member and writer as the “Duchess of Dirt” 

September Garden Chores

Here is a listing of what should be attended to this month:

  • Divide those perennials that have grown too big and distribute their beauty to other garden beds…or donate them to the plant sale!
  • Gather seeds from your annuals; dry them out well and store them in envelopes or paper bags over the winter to start a new batch of annuals next spring.
  • Turn the compost pile over.
  • Plant your winter vegetable garden with such goodies as oriental greens, winter lettuces, spinach, kales, shallots.
  • Plant spring-flowering bulbs. Some suggested varieties include daffodils, tulips, anemones, muscari, alliums, scilla, etc.
  • Treat your lawn to some low nitrogen, high phosphorous fertilizer now for rewards of green pastures come spring.
  • Worn a path to the shed? Sprinkle some soil down on the worn areas and sprinkle a little grass seed. Too well worn? You may want to think about putting in pavers, gravel or bark mulch to make a proper path.
  • Nights will be getting cooler…time to start bringing those tender plants into the house.
  • Do a final light trimming on hedges.
  • Prune your summer-flowering shrubs such as Philadelphus (mock orange), Deutzia, Syringas (lilacs), etc.
  • Start a new pile in the compost bin as you do your fall cleanup.
  • Just have to have winter colour? Check out the winter pansies and ornamental kales that are arriving in the nurseries now.

 

Article submitted by Leslie Cox
CVHS member and writer as the “Duchess of Dirt” 

March Garden Chores

Here are some suggestions of what should be done in the garden through the month of March:

  • If you have not finished pruning the fruit trees and grapes, get on it! Days are warming and sap will be flowing, grapes especially. Leave it too late and you run the risk of awakening pests being attracted to freshly made cuts.
  • Remove dead fruit canes in the berry patch. Strengthen support wires.
  • Prune blueberries, gooseberries, currant shrubs now. Concentrate on shaping young shrubs up to two years of age, then prune for keeping the shape open to allow good air flow through the shrub, lessening the chances for pest and disease infestations.
  • Prune back late-flowering shrubs, such as spirea, hydrangea, buddleja (butterfly bush), cotinus (smokebush), and roses.
  • Prune back Group ‘C’ (or Class 3) clematis to about a foot (30.5 cm) high. If you do not know which group your clematis belongs to…Group ‘C’ clematis are those which come into flower in mid-June and continue flowering until fall.
  • If you left your late grasses (Miscanthus sp.) standing for their winter interest in the garden, cut back now before new leaf blades appear.
  • Continue with other winter cleanup that needs doing, being careful about walking on the garden beds. If they are too water-logged, you risk compacting the soil.
  • Sprinkle wood ashes (potash) around the berry canes and alkaline-loving plants such as clematis vines.
  • Plant deciduous trees, shrubs, hellebores, winter pansies, etc.
  • Turn the compost and screen it. Top dress the garden beds with this wonderful soil amendment.
  • Prepare the vegetable garden as soon as the ground allows. Amend with rich compost, seaweed, or well-aged manure.
  • Direct sow peas, arugula, radishes, pac choi, choi sum, corn salad, spinach, kale, collards and broad beans. Can also direct sow sweet peas.
  • Plant garlic now, if you missed planting in September / October…but get it into the ground before the middle of the month.
  • If you have grow lights, good lighting indoors, or a heated greenhouse…sow these varieties now:
    • vegetables: broccoli, early cabbage, cauliflower, lettuce, leeks, sweet onions, celery, peppers, eggplant, tomoatoes, and bulb fennel.
    • herbs: chives, mint, lavender, rosemary, thyme, oregano, summer savory, and sage
    • flowers: calendula, hollyhocks, columbines, Echinacea (cone flowers), marigolds, nasturtiums, and rudbeckias (black-eyed Susans). (This is not a complete list by any means. Check your seed packets for sowing instructions.)
  • Pot up dahlia tubers and canna bulbs to give them a head start.
  • Direct sow carrots, parsnips, endive, and radicchio the last week of March, weather permitting.

 

Article submitted by Leslie Cox
CVHS member and writer as the “Duchess of Dirt” 

Open Garden Tour – April 19, 2015

Open Garden Tour of two members’ gardens: Ann Chevrier and Joan Wynden
Date: Sunday, April 19, 2015
Time: 12:00 p.m. to 4:00 p.m.

Please note: These gardens are only open to CVHS members and their guests. If you would like to become a member, please follow the link to our Membership information page here.

Ann Chevrier Garden
Ann’s garden has quite a few rhododendrons which are already putting on displays. There are about 150 rhodos which extend the display for over a two month period or longer. There is also a pretty crevice rock garden. It was designed and built by Dany Fortin one year ago and is looking quite settled now. Two wee ponds and a small waterfall built by Angie Richardson of Guided Gardening & Design are also sure to delight garden visitors. Ann is very pleased to be sharing both of these newest additions to her landscape with us. Definitely a must-see!

Joan Wynden Garden
Joan has a well-established shade garden in her backyard. There is a greenhouse where she does lots of propagating. Her garden in the front yard is terraced with lovely trees and shrubs. This is also where you will find the raised vegetable beds because there is plenty of sun in this part of the property. You definitely do not want to miss this garden as there is a lot of diversity in a relatively small space!

For more information about this Open Garden Tour, please check the April newsletter or contact the Coordinator at gardentours@comoxvalleyhortsociety.ca on our Contact Us page.