How to take cuttings and collect seed for a new generation of plants
We all do it - we all take trips to our favourite nursery just to look around. What starts out innocently as mere window-shopping inevitably goes awry. An hour later and our trunks are full of plants... and our wallets are decidedly empty. Next time, instead of heading out to the nursery, step into your own garden and take a good look around. Everything you need could be right under your nose. It may even save you from wasting hundreds of dollars on plants you really don't need. You may already have all the elements of a great garden, but for whatever reason, you may not be using them to their best advantage. Perhaps plants are in the wrong spots - some may be overused while others are under-utilized. These are common mistakes. As gardeners, we are prone to want too much. The "I just have to have that" mentality that curses us all can lead to a garden of unorganized excess. It may be time for a systematic overhaul of the way you approach your garden. In every garden there is potential to utilize what we already have, but in more effective ways. Treating your garden as a resource may require a bit of foresight and planning, as well as a modicum of effort, but you will enjoy the results on every level - visually, emotionally and financially.
Summer is the perfect season to take stock of your garden. Turning a critical eye to your garden when it is in its prime will allow you to focus on what works and what doesn't. By doing so, it is possible to build upon the positives that exist, while eliminating some of the negatives. You may end up removing plants that are not performing, taking note of those that are doing especially well, and uncovering the reasons why. Instead of adding new plants to your garden, why not increase the numbers of those that are already performing well? Collecting seed and taking summer cuttings are two easy ways of doing just that. Before you get started, there are a few basic principles that you need to know. Entire books are written on these subjects. I will touch on a few basic methods and techniques, but I suggest finding some good reference books to help answer any specific questions, such as figuring out the correct time of year to take cuttings of various plants or determining when seeds are ripe for harvest, which will vary from species to species. Much information is available on the Internet and doing a simple search can bring answers very quickly, without the need to purchase reference material. So grab a pen and some paper and step into your garden. Try to look at it with a fresh set of eyes. Make lots of notes and don't be afraid to put down on paper what you really think. To start, make two lists: plants that work and plants that don't. And be harsh. Just because you spent $24.99 on a hellebore you were told you "just had to have" doesn't mean it was the right plant for you or your garden. Sometimes the worthiest plants are the ones that cost the least, or the ones whose names you aren't even sure of. Whatever the case, you have to systematically determine the good, the bad and the ugly, without prejudice. This may be the hardest gardening task you ever ask of yourself. From your list, you will discover the performers with which you will create a new generation of plants to fill the voids and problem areas of your garden. It is from these plants that you will collect seed and take cuttings.
One of the most effective means of increasing plant numbers is by taking cuttings. Summer is a great time for this as plants are actively growing, producing healthy new shoots that are ripe for propagation. The season's increased light levels, longer day length and higher temperatures allow for maximum root initiation and growth. Cuttings are also an insurance policy for tender plants that are not likely to make it through our winters in British Columbia. Many Mediterranean plants and those from the Southern Hemisphere that have become popular in the last few years are less likely to withstand our low temperatures and wet winters. It makes sense to re-propagate these to ensure their survival from year to year. With a few tools and supplies, the average gardener should be able to use cuttings to propagate successfully. The most common type of cutting will be a tip or nodal cutting, where an eight- to 10-centimetre shoot is excised from the mother plant. Once cuttings are taken, process them as quickly as possible. Remove the lowest set of leaves from the shoot to expose nodes from where the roots will initiate. At least one set of nodes should be present for roots to develop. Dip the exposed nodes into rooting hormone. The cutting is then ready to be "struck," meaning that it can be placed into a pot filled with a rooting medium. The medium should be loosely packed allowing for optimum oxygen in the rooting zone. Depending on the size of the cutting, many shoots can be placed into one pot. For plants that are exceptionally leafy, such as geraniums and fuchsia, leaf reduction is recommended. Using secateurs or a knife, trim up to one half of the leaf area away. This helps reduce the amount of wilting that occurs from transpiration, as well as allowing for better air circulation and maximizing the number of cuttings per pot. Once the cuttings are struck, water the pot heavily, to the point of run-through, as this may be the last time the cuttings are watered until they root. Place the pot in a plastic bag or under a plastic dome to provide the cuttings with constant humidity. Cuttings should be placed in a bright, warm location, away from direct sunlight. (Any sun will effectively cook your cuttings.) It is wise to check your cuttings daily and open and close the humid environment, allowing for a transfer of air. This gives you a chance to see if the cuttings need anything, such as water, misting, or removal of mouldy tissue or dead cuttings. Note that not all plants are grown from nodal cuttings. An exception is the genus Clematis, where root initials occur from stem tissue and not from buds. Some woodier cuttings also require a heel (a piece of the stem from the mother plant, common with conifer cuttings) in order to root. Do some research to determine which type of cutting is appropriate for the plant you are trying to propagate. Now you can sit back and wait until the cuttings have rooted. The amount of time for root initiation will vary from species to species. Fuchsias can root within seven to 10 days under optimum conditions. Rhododendrons and other shrubs can take months. Once the cuttings have developed substantial root systems of their own, remove them from the humid environment and pot them up. They should be grown on in pots until they are needed the following year. With tender material, protect the plants in a greenhouse or indoors for the winter, whereas you can heel-in the hardy material outdoors until use the following spring. A great reference book is American Horticultural Society Plant Propagation: The Fully Illustrated Plant-by-Plant Manual of Practical Techniques, by The American Horticultural Society and Allan Toogood (1999).
- Once you have determined which plants merit re-propagation, a few basic rules should be followed before starting:
- Take cuttings from healthy plants, avoiding any diseased tissue.
- Take cuttings early in the morning or late in the afternoon when the plant is more turgid and less likely to wilt from the heat of the day.
- Avoid taking too many cuttings at once, taking only as many as you can process before the cuttings lose viability or wilt.
- Take cuttings of vegetative shoots without flowers or flower buds. This will ensure that the cutting's energy will be channelled into rooting instead of blooming.
- Sterile rooting mix - a 50/50 mix of peat and perlite is both porous yet water-retaining.
- Secateurs/cutting knife - clean and sharp to take cuttings.
- Pots - sterile 9- to 15-centimetre size.
- Rooting hormone - in the appropriate strength for the type of cutting. Rule of thumb: woodier cuttings require stronger hormone.
- Plastic bags/clear plastic domes - help maintain humidity around cuttings. Zip-loc vegetable bags (with perforations) are ideal, maintaining humidity while allowing for air circulation. Clear plastic domes can be placed over many pots in one flat.
- Bucket of water/plastic bags - placing cuttings in water or a plastic bag ensures freshness until cuttings can be processed.
- Spray bottle of water - for misting.