How to increase your stock of garden plants
HANDS up if you have any of the following and would like a few more: flowering currant, dogwood, forsythia, butterfly bush, Philadelphus, Weigela, lavender and honeysuckle. Well, we are in the middle of July and I have some good news for you. Now is the ideal time to create clones of all the above plants with ease.
To propagate them you will be taking semi-hardwood cuttings and, as the name implies, being hard in stem they are harder to kill than other cuttings. Semi-hardwood cuttings have the advantage of containing a substantial reserve of stored energy, which allows them to root even in poor light conditions.
The ability to produce roots without the need for direct sunlight has two further knock-on advantages. The main one is that you can locate your cuttings in a partially shaded spot and not worry about the prospective plants drying out should the sun get intense. A further advantage is that you are not giving over valuable “full sun” real estate to cuttings when you have plenty of sun-worshipping plants that would be only too grateful for the location.
You will not need a glasshouse or polytunnel to pull off this propagation lark, just a few simple items that most home gardeners will have lying around.
Making the cut
To start, take a cutting about 22-23cm (nine inches) long from a shoot produced this year, then nip the soft top off the cutting, leaving it 15cm (six inches) long. Create a straight cut across the base just below a leaf and a bud and then remove all the leaves up to halfway on the stem. The lower portion of the stem will be going into the soil, so leaving any foliage on it would only invite rot.
Now that we are on to the nasty subject of rot I feel I should say a few words about rooting powder. Some gardeners are dubious about its root-promoting potential, but I suggest you use it, if only for its anti-rot properties. You see, most of the rooting powders available contain a fungicide in their formulation, so for the sake of a few Euros I would use it in the hope that it promotes growth while discouraging rot.
A little tip I use to ensure a good even coverage of rooting powder is to dip the end of the cutting into water and then into rooting hormone powder. Next you introduce your cutting to its growing environment of pots filled with cutting compost from the garden centre or a homemade 50/50 mix of sharp sand and peat moss. I find a nine-inch pot filled with such mixes will accommodate two to three cuttings comfortably.
Use a pencil to create holes for the cuttings in the compost to avoid the loss of the rooting powder when you insert them into the rooting medium. The holes should be far enough apart so that the individual leaves of the cutting will not touch and rot. You place the bare stems into each hole and firm it lightly with your fingertips, followed by a thorough watering, without disturbing the soil too much.
The second to last task is to cover the pot with a clear plastic bag to create your own mini-greenhouse. We must not allow the bag to touch the cutting as again rotting can occur, so to prevent this I advise inserting three to four narrow canes into the pot to support the bag. Finally make sure you secure the clear plastic bag to the pot with a rubber band and stand the pot in an area away from direct sunlight, either inside or out.
The humidity inside the plastic covering will keep the cuttings moist while new roots are being formed. Once some substantial new growth appears on the individual cuttings (usually takes three to four weeks) they can be transferred to individual uncovered pots to grow on over winter with a view to planting out the following spring.
As I said — easy — so give semi-hardwood cuttings a try and you may end up with more plants than you know what to do with. It’s not really the worst complaint, in fairness.
Until next week, happy gardening and remember that a weed is just a plant in the wrong place.