How to handle spotty rhubarb and more
Q Can you please tell me how I can take cuttings from a cotoneaster? I would like to start a long hedge, but if I buy the plants it would cost a fortune. I’m hoping to just take cuttings. A The two methods you can use are softwood and semi-ripe cuttings. I would recommend using the softwood method. These cuttings are taken in spring from fast-growing stem tips. The advantage to this method is that these cuttings have a soft base and a higher capacity to root than more mature wood.
Take the cuttings early in the morning, selecting healthy, pliable, single-stemmed shoots, and place them in an opaque plastic bag. Prepare these cuttings as soon as possible after collection. Trim the cuttings to eight to 10 centimetres, making a straight cut just below a node. Remove the lower leaves. An absolute must is to use a very sharp knife or pruners. If the knife or pruners are at all dull they may crush the stem or tear the bark.
The cuttings soil mixture should be a mix of equal parts peat moss and either perlite or sharp sand. Insert the cuttings into the soil mix and water them in. It is a good idea to apply a fungicide to minimize the chances of rot. Insert the cuttings into the mix, ensuring that the leaves do not touch each other.
The use of a rooting hormone is a good idea if you want to ensure your success rate. You can find the rooting powder in most garden centres. Make sure you select the one for softwood cuttings, as there are different types.
Softwood cuttings wilt quickly if not kept in a humid environment. You can cover the pots or flats with clear plastic and keep them out of direct sunlight. Air them out every few days for good air circulation or leave one side of the cover open slightly. Keep them at a temperature of 18 C to 21 C.
Once the cuttings have rooted harden them off. Remove the rooted cuttings from the pot or flat, carefully teasing them apart. Transplant these into individual pots firming them in. Water well and keep them in a shaded spot until well established.
Q Once again I am having problems with rhubarb. A couple weeks ago I purchased a new clump called ‘Canada red’ but already the leaves are spotty and I’m wondering if it is some kind of rust. This new plant I put in a totally new location from where our previous rhubarb was, but it seems to be developing the same kind of problem. I should mention one of the larger leaves already had brown spots when I purchased the plant, but I just thought it hadn’t been watered sufficiently at the greenhouse. I so enjoy baking with rhubarb, but am becoming disheartened at growing any and my friends all ask “how can you not grow rhubarb, it grows anywhere.” Ha! I know because I have seen it growing in back alleys where it is totally ignored. If you have any suggestions as to what the problem could be, I would appreciate hearing them.
A I sent your email and the photo you enclosed to my friend, retired plant pathologist Dr. Ieuan
Evans, to see if he knew about the spotty rhubarb. As usual, he had the answer:
“Don’t worry about the spots, they are not infections. This rhubarb has just been planted and we have just come through a dry spell. Water it well until the end of August, at least heavily weekly. Keep it well watered next year and feed it a 20-20-20 type fertilizer next year at a teaspoon per gallon in April, May and June (once per month). Don’t expect to harvest any stems until the third year and then never more than 50 per cent at any given time.”
Q How do I get rid of crab grass? A I believe you might be referring to quack grass and not crab grass. If I had the simple answer to this question I would be a very rich man. Unfortunately, I don’t have that answer.
The advice I can offer is to keep your lawn well fertilized and watered. That will help keep the good grass strong and will help in keeping out the quack grass, or at least in keeping it under control. If you regularly mow your lawn you really don’t even notice the small patches of quack.
In the dark ages I used to recommend using a glyphosate herbicide and painting it on the quack, but I don’t recommend using that any longer because of health concerns. Good luck and happy gardening!