Got green thumbs? Need to make them greener?

680News gardening specialist Mark Cullen answered your questions live on the web Thursday from noon to 1 p.m.

Here we go. I’m Diana Pereira, editor of 680News.com. Thank you, Mark, for being here today. With the sun finally shining, people want to know how to take care of their gardens. Let’s get started.

QUESTION
From: Ira and Dr. Graciela D’Adamo

Thank you for the opportunity to ask Mark a professional who we admire very much.

We have a little problem in our backyard: a big and healthy pine tree, surrounded by poison ivy. My husband has a very bad case of skin problem during the summer due to the poison ivy. The question is: is there any natural way to get rid of the poison ivy without damaging the pine?

Thank you very much in advance.

ANSWER
There is currently nothing on the market that you can effectively spray on the p.i., but the most effective ‘natural’ way to deal with it is to cover the are with black plastic a.s.a.p. and leave it in place for six to eight weeks. The roots of the p.i. will ‘cook’ and disappear.

QUESTION
From: Tara Van de Laar, Niagara Falls, Ontario
Thank you Mark for all your good advice. My question is how and when do I take a clipping from a well-established (over a hundred year old), rosebush. I do not want to harm the rose bush so I have been hesitant to do so. Thanks again.

ANSWER
I assume that you are interested in propagating your rose. If it is over 100 years old it was not likely grafted or budded which means that it must be on its own root. One way to propagate your rose is to layer it – pull an existing cane down to the soil and bury it, leaving some remaining stem above the soil. Score the bark of the cane first where it makes contact with the soil first and hold the soil in place with a brick or two. Do this ASAP. Come spring the cane portion that is submerged beneath the bark will have developed roots. Cut the cane off leaving the roots and existing cane in tact. You now have a new plant! Do this with several canes as it does not always work.

QUESTION
From: Susie Louie
We have a peony plant growing in a planter. We’d like to move it to the front yard. Is this possible? Will the plant survive the move? What time of year is best to move it? Thanks. Stay in touch.  

ANSWER
A peony will move to another part of your yard at any age. Dig as much of the roots out at one time and move with all roots in tact or separate the root mass and divide it two to five times. Each division should have three to five growing ‘eyes’ on it.  The best time to move a peonie is in mid September.

QUESTION
From: Elaine Harman
Hi Mark, I usually put out my Jade plants in the summer and they seem to flourish (almost double in size), however last year they didn’t do as well and the leaves went a scaly brown. I brought them in and they are doing fine again, but what did I do wrong last year, and how can I put them outside again this year? Thank you.

ANSWER
I doubt that you did anything wrong – the weather last summer was extremely wet and cool. The opposite of what your jade likes most – hot and dry. Judging by all of the long range forecasts that I hear, this may be an ideal summer for your jade. Be sure not to over water it and put it in a sunny position.

QUESTION
From: Mary in Brampton
Hi Mark, I have a long area of garden along a cement privacy fence, but the dirt is old and hard. How do I prepare this for planting some flowers? There are some perennials in one area and I am afraid of digging them up if I turn the dirt. I thought if I just added more dirt the rain would wash it away. Thanks.

ANSWER
Brampton: poor soil. I suspect that you will have to dig the whole bed out about 40 to 50 cm. deep. (Brampton is famous for it’s clay – and for making bricks with it.) After you have the clay removed backfill with triple mix (one third each of top soil, peat and compost) and make sure that it over fills the bed by 10 cm above grade.
If I am wrong about the soil and the quality is recoverable, add generous quantities of compost and sandy loam. To know take a sample to Humber nurseries from the existing bed. If you move the perennials now it is not too late – a couple of weeks from now may be a problem.

QUESTION
From: Kris Jones
What is the quickest, easiest, most cost-effective way to revitalize the soil in my garden? I have topped up the beds with compost and “extra nutrients”-type soil but, because of the density of roots from my trees and shrubs, it is very difficult to turn the soil to incorporate. Also, the gardens are built up from a bed of clay – I live in Mississauga – so I can’t dig too deep anyway. Any suggestions?

ANSWER
You situation is complicated by the trees/shrubs.  Without them I would recommend that you dig down 50 cm. as per the previous question – backfill with same. But if the large trees and shrubs are numerous and aggressive by nature I would suggest that you top up the soil with about 10 cm. of triple mix and plant a ground cover there. Ground covers that would work include pachysandra, lily of the valley, Baltic ivy.

QUESTION
From: Greg Brown
A few years ago I moved to the country, and discovered that my new vegetable garden grows great weeds. I do weed, but in 2009 the weeds won. I was told that burning organic materials like leaves and sticks, every 5 – 10 years might help the soil, and inhibit the weeds. What are your thoughts?

ANSWER
Interesting concept and only one that would work in the country where you can burn stuff. I am skeptical that this will get rid of your weed problems as the roots will 0- for the most part – remain unaffected. Better to cover the area with black plastic for six to eight weeks and cook the weeds – roots and all. Or mulch the area heavily with 50 cm of loose straw after planting. In any case be sure to add lots of compost to the soil before you turn it over.  

QUESTION
From: Dante
Hi Mike,
How do I prune a Wisteria? The plant is several years old and it has never flowered. This year there are a lot of branches that are bare and they look like they should be pruned. I am worried that if I cut these I may cause further damage to a plant that looks like it needs help. We planted the Wisteria on the south side of the house, and it well sheltered and it get lots of sun. Help!
Thank you.
P.S. We live in the Caledon area.

ANSWER
Wisteria is a tricky one to get to reflower – generally it refuses to flower when it gets ‘lazy.’ The solution is to cut it back very hard with clean, sharp hand pruners.  Cut back by 1/3. Also root prune with a sharp spade by pushing the spade around the drip line of the wisteria about a meter out in diameter from the main stem.  Finally apply super phosphate 0-20-0 – about two or three hand fulls to the soil around it now again in June and again in late October.

QUESTION
From: Anupal Singh
Dear Mark Cullen, I have questions primarily related to Lawn and Watering.

1. How does one get rid of all the weeds? I didn’t have time to spread any fertilizers or do any over seeding during the spring. So if I had to start tomorrow, what can I do now to enjoy a healthy lawn during this season? 

ANSWER
Over seed your lawn now with a good quality triple mix of lawn seeding soil [I have a Mark’sCHoice product at Home Hardware]. Apply quality seed evenly over the whole area at the rate of one pound per 400 sq ft.  rake smooth and keep watered for six to eight weeks. Fertilize now with Golfgreen. Leaving this job until it gets very hot and dry will not help your  lawn. 

QUESTION
2. My lawn is also very bumpy to walk on. How do I repair this?

ANSWER
Spread quality triple mix over the entire lawn, filling in the valleys and evening out the tops of the  mounds.  A light rolling will help but only fill the lawn roller 1/3 full of water.  Otherwise compaction occurs.  I use triple mix from the Cutting Edge Soils – Nick delivers everywhere in Toronto including the beaches and his product is A 1.

QUESTION
3. How often does a lawn require watering? My neighbour waters his lawn everynight with the sprinkler system. I too have a sprinkler system installed, but is it required to water everynight? Is it not being over watered? Some people say to water once a week for half an hour is perfect, while others say to do it for 20 minutes but 3 times a week. What do you think?

ANSWER
ONLY water your lawn once a week – at most. But water apply about one inch of water on your lawn when you do. (Three to four hours for most sprinklers) this will drive the grass roots deep into the soil making them more drought resistant and you lawn healthier.  Be sure to fertilize with good quality fertilizer this time of year. 
If you have an in ground sprinker put it on the manual setting and turn it only when your lawn needs watering. 
It a drought situation do not water at all.

QUESTION
4. I have many of those evergreen plants that are like 5-8 feet tall. Problem is, a good portion is brown and no matter how much I water them, it doesnt change. Does it mean its time to replace it? or can it become lush green again?
Thanks in advance.

ANSWER
A light pruning is in order – just shear the first cen. Or two off with sharp pruning shears.  Fertilize with evergreen food 30-10 -10  or ‘once and done’ for evergreens.  Do not water unless newly planted or if we are in a drought…. Junipers generally like to be on the dry side… problem here could be overwatering.

QUESTION
From: Nancy Sheridan
Hello, I would like to know how to properly trim my rose bushes so they won’t go wild?

ANSWER
I assume that you are talking about the growth from the base or  root stock of a grafted [budded] rose bush. The answer is to remove the growth that looks ‘wild’ as it occurs from the base of the plant. If you have a winter hardy shrub rose  you can prune it hard by up to half and thin the oldest growth out of the middle of the plant to freshen it up.

QUESTION
From: Mary Ward
Hi Mark,
We have a flowering crab tree that has certain branches that are dying off. the bark is falling off the tree in certain areas. should we cut off the dead branches? is there anything we can do to save the tree?

ANSWER
Cut off the dead branches and take a sample of the cut material into a local garden centre to have a professional look at it and advise you. The problem could be many things.

QUESTION
From: Elaine Salisbury
We have some large walnut trees in the yard behind us in North Toronto. They overhang our yard and we can’t seem to grow anything in the back part of our yard. Grass dies, plants die – only weeds seem to thrive. Is there something we can plant under these trees? We are tired of reseeding and planting each year. Thanks.

ANSWER
If weeds can grow there so can ‘desirable’ ground cover.
Some of the best for this situation include lily of the valley, pachysandra (evergreen) and Baltic ivy (also evergreen) when you plant add five cm of quality triple mix.

QUESTION
From: Sandy Kumar
My lawn is full of dandelions. Last year I had the same problem in the front yard and I have completely scrapped all the grass in my front lawn. Half of that I paved to extend the driveway. The rest half I filled with top soil to plant flowers. For the backyard I believe the same solution will hold good as to how many dandelions am I going to pull out. Is there anything I can do? Thanks.

ANSWER
There is a new dandelion killer on the market that is biological – non chemical.  Sarritor.  It must be applied when temps are below 20 degrees so now is a good time. Otherwise I would do same as question # 9 – overseeding.

QUESTION
From: Piyush Aggarwal
Hi, I have a big cherry tree in my backyard with white flowers currently. It bears cherries every other year. Last year I did not get many cherries and had wilted leaves with black ends of branches and eaten leaves. The fruit was also half eaten with black insects. I would like to know at what time I should go for the spraying of the tree and what kind of spray should I use. Thanks.

ANSWER
Spray with dormant spray in mid April to kill overwintering disease and insects.  Begin to spray again in early June – after blossom drop – with combo of insecticidal soap and lime sulphur, according to directions.  Both are safe to use. Sulphur smells unpleasant – do not apply it when expecting dinner guests.

QUESTION
From: Tyler Schram
There are a ton of mole holes around my pool. They are destroying my lawn. How do I get rid of them?

ANSWER
Juicy fruit gum. Chew it first and stuff it into their runs. It will gum up their works.  And it works.

QUESTION
From: Evy
Hello Mark Cullen
What is a good organic weed killer, especially for dandelions. I live next door to a park so am getting the dandelions seeds blowing to my side. I have so many that pulling them out is not an option anymore.
I have tried dish detergent mixed with vinegar but it only seems to kill clover. Any help would be so appreciated. Thank you in advance.

ANSWER
Look for the new SArritor biological weed killer as per previous question. Apply now.

***

That’s all for today, everyone. Thanks for submitting your questions. Sorry we couldn’t get to all of them. Thanks to Mark for participating. 

Part 2

There were so many questions that Mark came back to answer more Friday, May 7. Here they are:

QUESTION
From: Susan McGarrell
Hello;
I would very much like to ask Mark how I can get rid of lily-of-the-valley which previously was behaving very nicely in the flower bed, but now has started to take it
over. It is a very large triangular bed in between a cement path and brick wall. There are other numerous perennials and these lily-of-the-valley are coming up right
in the middle of the clumps.
Thank you very much,
Susan McGarrell

ANSWER
This is the perfect time of year to literally dig the root and all of your lily of the valley up – if this means taking up the root of an existing perennial then just tease the roots of the l of v. out of the roots of the perennial and replant the perennial. 

QUESTION
From: Jennifer
My lawn is so dead, very dry, yellow and no where close to my next door neighbour’s. How can I save it this year?
Thanks
Jennifer

ANSWER
#1 fertilize with Golfgreen.
#2 spread triple mix (1/3 top soil 1/3 compost and 1/3 peat moss) over the area and over seed with quality grass seed.  Water well.  Go to www.markcullen.com  for details.

QUESTION
I would like to start a herb garden in a huge plastic container that I have and my question is what herbs are the most hearty to plant and can I use regular garden soil or should I use a mixture of manure and garden soil? Thank you.

ANSWER
1. Winter hardy herbs include oregano, mint, thyme and sage. 
2. ONLY use a good quality container mix – not soil from your garden.
3. plant in full sun and allow the container to get dry between watering.

QUESTION
I have an invasive weed/herb that’s virtually impossible to get rid of. It’s called Garlic Mustard and it spreads fast and invades every corner of my yard and flower beds. Can you suggest a way to get rid of this invader. I’ve been pulling them before they seed and that seems to be controlling the spread somewhat but they come back quickly. I have small kids so I’d like to avoid using chemical solutions.

ANSWER
No easy answer… many conservation areas and public gardens battle the same stuff!  You have the right idea pulling it up before it seeds – there is no other way to keep it under control.  Sorry.

QUESTION
Help, have alot of weeds. Is there any natural product or solution that I can use to get rid of my weeds?

ANSWER
Weeds in lawn or garden?  In garden -hoe them down now and mulch with pine or cedar bark mulch 6 to 8 cm. thick.  That will eliminate 90% of them.
Lawn? Over seed your lawn per question # to compete weeds out of existence and/or user Sarritor biological weed control.

QUESTION
How do you aerate your lawn – water first then aerate, then water again? When is it time to aerate, or is it too late?

ANSWER

IF you aerate do it now… while there is lots of moisture in the soil.  You do this only on clay based soils or where soil compaction has been serious.  Use a power aerator to do the whole lawn and leave the cores on the surface of the lawn -t hey will disappear in a week or two.

QUESTION
I want to overseed my lawn to block out weeds, how do you overseed?

ANSWER
Go to www.markcullen.com for details if you have further questions.  Home Hardware has a ‘care sheet’ available for free that explains the details if you are in a store.

QUESTION
Household vinegar is 5 per cent acetic acid. What is Horticultural Vinegar & how strong is it? Where can I buy it? HomeDepot, Rona, Cdn Tire, etc. don’t carry it.

ANSWER
Interesting question.
Green Earth Weed and Grass killer is 7 to 10% acetic acid [vinegar] and 2 to 3% emulsifiable plant oils.  House hold vinegar will not likely have an effect.  You should be able to find the product at a garden retailer…. Click here for more info.

QUESTION
Hi! My question is about bulbs. I planted tulips and daffodils last Fall, and the greens/leaves came up, but no blossoms. Did I plant them too shallowly, or do they just need some fertilizer or other nutrients?

ANSWER
Spring bulbs have all the nutrients that they need to produce a bloom.  You likely planted them too deeply and/or in heavy soil or a wet area.

QUESTION
Hi One part of the back yard (one side of a huge shady tree), the ground is cracked and no grass. Have tried several brands of grass seeds, no success. Please help me to grow grass on that area. Thank you.

ANSWER
You are fighting mother nature here and will forever… I suggest a grass substitute that is living like lily of valley, Baltic ivy or pachysandra.  Make sure you put down 10 cm. of triple mix before planting.

QUESTION
Are you supposed to trim back a butterfly bush? We planted two last year and one has leaves all over and the other just has leaves in certain parts of the bush… Also, can you prune and trim back a forsythia shrub this time of year after it has finished blooming?

ANSWER

Trim your butterfly bush to the green, leafy growth.  Cut back as far as you wish.
Forsythia should be pruned after blooming…. Any time now.

QUESTION
I have two overgrown euonymous bushes in my front yard. How do I cut them back without killing them? Better still, can I divide them somehow to replant in the backyard? The roots on these bushes are huge and tree-like!

ANSWER
Cut back by up to 1/3 without harm to the plant.
Do not attempt to divide them -they are a woody shrub/evergreen not a herbaceous perennial.
Though, you could take a slip from a branch that has rooted itself.

QUESTION
Hi Mark. Love your work….I live on an acre lot with lots of grass. I don’t water and I don’t fertilize much. I used to get a lawn service for weed control. Now the only product they are allowed to use is Sarritor, which apparently needs to be watered in and is expensive, so we stopped using the lawn service. Of course, now the weeds are starting to make a comeback. My question: are the lawn care suppliers working on products that work the same as 2,4,D et al while still being considered “green”? I’d love for things to be brought under control soon so that I’m not going back to the days of a lawn that is more weeds than grass…. Thanks

There is a product – the name of which I do not know – that is planned for introduction later this season… I do not a know a lot about it yet.  Meantime we have the aforementioned SArritor.

QUESTION
One of our ornamental trees has a bad case of black knot. It’s infesting many of the branches and even on the trunk of the tree. It is a beautiful tree. Is it time to cut it down or can it be pruned without it returning each year? Is there some product that will get rid of it?

ANSWER
Yes -cut as much of it out as possible now… no spray that will effectively control it.

QUESTION
What was the name of that biological weed killer that you mentioned yesterday on the air?

ANSWER
SArritor. Click here for more info.

QUESTION
I have a lilac bush with many blooms but very few leaves. How can I encourage more leaf growth?

ANSWER
Pull grass out from the neck of the shrub by about 30 cm.
Mulch with bark around the base and root zone
Fertilize with Green Earth Blood meal this time of year.