Thursday, March 21, 2013

Just Released: JUST ASK WIM!

Just Ask Wim!: Down-to-Earth Gardening Answers

by Wim Vander Zalm

HARBOUR PUBLISHING | March 27, 2013 | Trade Paperback

What vegetables can I plant as winter crops? How can I avoid bitter bolting lettuce? When is the best time to cut back rhodos? How do I overwinter my geraniums and fuchsias? What fastgrowing evergreen hedge will work for my narrow urban yard? How late can I plant spring-flowering bulbs? What should I do about the chafer infestation that is destroying my lawn? Why aren''t my berries bigger? What fruits and vegetables grow best in patio pots?

These are just a few of the burning questions that renowned gardening expert Wim Vander Zalm answers again and again as owner of two Art Knapp Plantland garden centres and a long-time regular on CKNW''s The Bill Good Show.

Just Ask Wim! covers horticultural concerns about all kinds of plants: vegetables, fruits and berries, herbs, annuals and perennials, shrubs, trees, hedges and vines, plus how to grow a healthy lawn organically . . . or replace the troublesome turf with one of many other groundcover options. Wim also shares organic pest and weed management ideas, common-sense pruning tips, fertilization and soil-building advice, plus his often-requested mulch recipe.

Friendly, funny and always down to earth, Wim is the guy to ask whenever there is a need to know about how to make the most of any garden--urban or otherwise. In addition, his comprehensive Get It Done! checklist takes the reader right through the year, month by month, pinpointing just what to do and when for a stress-free, successful gardening experience.

Saturday, November 10, 2012

Acidic Soil

Q: What shrubs or plants will survive in an acidic soil and full sun in summer. Cedar tree in the next door neighbor’s yard does carry over?

A: Having cedars in and around ones yard can be challenging for those who want to grow a variety of trees, shrubs and perennials that do not like an acidic soil. When a soil is excessively acidic, many plants will struggle for varying reasons. The one thing that you will have an abundance of is moss though.

To combat that situation you can add copious amounts of lime 2 or even 3 times a year to raise the ph of the soil and that is an relatively effective way to improve the growing conditions for many plants. You may however want to consider simply planting plants that are tolerant of a low ph soil.

Below are a number of Shrubs, Trees, and perennials that I like and that I know you will have success with in an acidic environment.

Viburnum Davidii zone 5-8
Blueberry plants zone 2-8
Yew zone 4-7
Skimmia Japonica zone 7-9
Heavenly bamboo zone 6-8
Alberta Spruce zone 2-7
Osmanthus zone 5-6
Pieris Japonica zone 6-7
Some varieties of Rhododendrons
Mahonia, Barberry zone 5-10
Kalmia, Mountain Laurel zone 4-9
Witchhazel zone 5-8
Acuba zone 7-10
Flowering Quince zone 5-9
Enkianthus zone 4-7
Hinoki Cypress zone 4-8

Stewartia zone 5-6
Japanese Snowbell zone 5-9
Norway spruce zone 2-7
Star Magnolia zone 4-9
Liriodendron, tulip tree zone 4-9
Liquidamber, Sweet Gum zone 6-9
Flowering Dogwood zone 3-9
Kousa Dogwood zone 3-9
Beech zone 3-9

Rudbeckia zone 4-9
Aquilegia, Columbine zone 4-10
Heather zone 5-7
Chrysanthemum zone 4-8
Foxglove zone 5-9
Salal zone 3-8

Fungus Gnat on Plants

Q: A year ago I used unsterilized potting soil for my indoor plants so ended up with little flies (like fruit flies). I spoke to someone at a plant store and she suggested that I take all the plants out of the soil and hose them off and then put them into the proper soil. I did that but in the last 5 months, the little flies have come back. Is there some solution that I can put into the soil to kill these?

A: You most likely are dealing with a fungus gnat. Irritating little flies that can be detrimental to your plants because they feed on the roots. They are a short lived fly but their reproductive skills are impressive and that's why it seems like there is a continuum of an growing population. Although there is commercial insecticides available at your local Garden center that will control fungus gnats in the soil of your houseplants, one of the best methods of control is simply by letting the top layer of the soil of your houseplants dry. You may even want to consider scratching the surface of the soil to help it dry out faster and more evenly. Fungus gnats can only reproduce within a moist soil environment and so eliminating the breeding ground is essential to eradication.

Holly Tree

Q: We have a 30 foot holly tree that is probably more than 40 years old. We live in Lynn Valley in North Van. About 3 years ago it started losing leaves. At first the barren area was in the shape of a small bell from the bottom up about two feet. The barren area is now all the bottom and up to about six feet. I have talked to an arborist and various nurseries on the North Shore. With their advice I have raked the dead leaves away and fed a fertilizer (18-4-8) at the drip line but it keeps getting worse. The leaves that fall off or are soon to fall off curll up, some have black spots and most have sort of brown burn marks on their edges. The tree is at the end of a hemlock/cedar hedge so I realize it must compete for food. There is also another holly tree further up the hedge also suffering the same leaf losses. Is there a disease hitting the holly trees as I heard there are other hollies that someone working in the tree cutting business told me he had seen? Is there anything you could advise that I do? This is a beautiful tree that we don't want to lose it.

A: It sounds like your Holly tree is definitely suffering from a disease or a bug. Holly Trees are prone to getting scale insects. These are insects that are secured to smaller branches and create this protective barrier over themselves. The best way to describe it is they look like little warts on the tree. They suck the nutrition and moisture that would otherwise go to the leaves causing the leaves to yellow and curl. The insecticide to control Scale insect is Malathion. The organic alternative is to spray the tree as well as applying a soil drench with Neem oil. There are also a number of fungus problems that can infect holly trees with very little means of control.

Based on scale being so prevalent on Holly I would suggest that you very closely examine the tree in May when scale becomes very active to see if they are the culprits, particularly as the tree is showing the results of scale infestations. One last tip. Make sure that the tree gets regular deep watering through the dryer part of summer.

Transfer plants

Q: We are digging out our backyard to put in a patio. There are two plants there - one wisteria and one clematis. Is it possible for us to dig these up and transfer the root system to large pots to keep them where they are, but not in the ground. If yes, what size pots would you recommend?

A: It is possible to transplant older Wisteria and Clematis for moving elsewhere in your yard or into a container like you'd like to do. Timing is important and the ultimate transplanting time would be March. You can still do this in April but try to pick a period when it will be overcast and rainy if possible. This will stress the plant less and it will also then be less likely to sustain transplant shock. If possible always move any plant that has been dug to it's new location as soon as possible. Prepare the hole or container using a combination of fresh earth, compost, manure, and peat moss. This will not only allow new roots to grow quickly and easily into the new soil but plants will perform much better long term when they're growing in a good mix of assorted mediums. When choosing the container, have in the back of your mind, bigger is better. Vines have a massive amount of leaf mass and during hot periods they lose a lot of moisture through transpiration (sweating so to speak) and all that moisture needs to be replaced. If you're container is too small it will dry out quickly causing damage to the vines.

I would suggest a 3 foot by 3 foot by 3 foot deep container to house your vines long term. Maybe building something with treated wood might be best. Immediately after transplanting ensure that you use a high phosphate transplanting fertilizer to feed the vines and assist in developing root growth as well as preventing any transplant shock that can damage or potentially kill your plants. Keep them moist from then on.

Arbutus Tree

Q: I live in New Westminster, my soil has great drainage and I would like to grow an Arbutus tree. It would face south, but I've heard they don't grow well except on coastal rocky areas. Would you recommend trying and do you sell Arbutus trees.

A: You heard right. They only really grow well in as you say, coastal rocky locations. I would highly recommend that you choose another tree. You're better off trying to grow a tree that will not give you any challenges and one that will naturally thrive in the environment in your yard.
Select a tree taking into consideration your desired specifications starting with your specific zone, the exposure, height and width, care requirements, blossoms, fall colour or any other attributes to fit the specific location. Take advantage of at experts in your local garden centre. Show them a picture of the area that the tree is to be planted and choose from a minimum of 3 suggestions. Always ask what drawbacks there are to each tree suggestion to help you determine which tree would be best for your yard. Care and maintenance play a vital role in selecting the perfect tree so take some time investigating as your new tree will be with you for a long time.


Q: I have an indoor Myrtle which is about 12" tall. I have had this plant for almost two years now and it is starting to look like it's on its last straw. The leaves are drying up and while most are still on the branches, a good shake will drop quite a few leaves. I have kept it in indirect sunlight and with moist dirt. There is some new growth off the top branches, but there are just a few leaves. I don't see any mold or bugs on it and I'm not sure if the plant needs a larger pot, or if it needs the dirt to be replaced every so often, as I have not done so for over a year. Also, a few months ago, I trimmed the top off of the plant and am not sure if its decline was due to over trimming.

A: A Myrtle always suffers indoors over winter. They're not truly an indoor plant. Our dry homes over winter coupled with very low light levels makes it a tough one to have success with. Find a cool room to keep it in now until late May at which time I would suggest placing it outdoors for the summer. Trim whenever you want as this won't affect the plant at all. Bring the plant back indoors in fall and find a cooler room with a big window to keep it. You can keep it indoors with success over the summer months but for recuperation purposes, this year I would put it outside for the summer as they'll recuperate faster outside. Transplant it if and when you know that it is going to survive. Remove any dead branches and ensure that the plant doesn't go dry. One really bad drying out and the plant will almost be guaranteed to loose over half of its leaves.