How to Take a Cutting: aka Asexual Propagation
With the chance of cold weather arriving soon (the average frost date in North Texas is November 15th), you might want to spend some time in the garden taking cuttings of favorite plants - or tender perennials that will not survive the frost.
Many types of plants, both woody and herbaceous, are propagated by cuttings. A cutting is a vegetative plant part which is severed from the parent plant in order to regenerate itself, thereby forming a whole new plant (these new plants are called clones).
Shrubs - Taking cuttings is the most popular technique for propagating most shrubs. Choosing the type of cutting and the ripeness of the wood best suited to a particular plant is very important to the success of the process. You can find specific information in propagation reference books, but in general late-summer through fall is the best time to take cuttings of semi-ripe plant material from shrubs. Semi-ripe means that the current season’s growth has begun to firm; the base of the cutting should be quite hard, while the tip of the cutting should still be actively growing (and therefore still soft). The length of the cutting is dependent on the growth habit of the plant being propagated, but between 2-1/2 to 6” is suitable for cuttings of most shrubs.
Shrubs suitable for propagating in the fall include Aucuba (Japanese Laurel), Buddleia (Butterfly Bush), Buxus (Boxwood), Callicarpa (Beautyberry), Camellia, Cotoneaster, Elaeagnus (Autumn Olive), Fatsia, Forsythia, Hedera (Ivy), Hydrangea, Hypericum (St. Johns Wort), Lavandula (Lavender), Ligustrum (Privet), Mahonia (Oregon Grapeholly), Nerium (Oleander), Pittosporum, Pyracantha (Firethorn), Ribes (Flowering Current), Spiraea, Viburnum, Vitex.
Perennials - You can take cuttings from some perennials at almost any time of the year they are not in flower; others are suitable only during a few weeks (or even a few days). Refer to a propagation reference book for information on specific plants. Depending on the stage of growth, cuttings from perennials can be taken from soft-, green-, or semi-ripe wood. The softer the growth, the faster it will root but the more vulnerable it will be to pests, disease and adverse conditions. Mid-summer through mid-fall is when most perennial cuttings are semi-ripe; stems will bend without snapping and will not crush readily. The length of the cutting is dependent on the growth habit of the plant being propagated, but between 2-1/2 to 6” is suitable for cuttings of most shrubs. Rooting will take from four to eight weeks.
Perennials suitable for propagating in the fall incude Acanthus (Bear’s Breeches), Achillea (Yarrow), Armeria (Thrift, Sea Pink), Artemisia (Wormwood), Bergenia (Elephant’s Ears), Dianthus (Carnation, Pinks), Diascia (Twinspur), Echinops (Globe Thistle), Eryngium (Sea Holly), Euphorbia (Spurge), Gaillardia (Blanket Flower), Gazania, Geranium (Cranesbill), Helichrysum, Osteospermum, Pelargonium, Penstemon, Peperomia, Phlox, Tradescantia, Tricyrtis (Toad Lily), Verbascum (Mullein), and Verbena (Vervain).
Taking cuttings from healthy, established plants won’t hurt them; often times it's good for the plant, but you should select stems carefully to avoid disfiguring the plant. Never remove more than 30% of the plant material at any one time, and when cutting from the plant, make your cut just above a node (where a leaf is actively growing, or where you feel/see a “bump” on the stem).
Choose plant material carefully to avoid any shoots where pests or disease may be present and discard any damaged material since this will be vulnerable to fungal attack. Do not propagate from a variegated plant that is showing signs of reverting to its all-green form. Take cuttings from stems that have new growth because these will root much more readily; most cuttings will be from wood of the current season’s growth.
Tools and cutting surfaces should be sterile to avoid the spread of disease. The easiest way to do this is to use anti-bacterial wipes (that don’t contain bleach) and insert your knife between the wipes before moving on to propagate another plant. Be sure to wipe both sides of the knife. Knives and razor blades are preferable to pruners because they cut plant material cleanly without crushing the stems.
Collect material early in the day when the plant it fully turgid (full of water) and before the sun diminishes the plant’s vital water reserves that have built up overnight. Store cuttings in separate, clean plastic bags (or buckets of water) and label them. If you are unable to prepare the cuttings immediately, place the bags/bucket in a refrigerator, where the cuttings will remain in good condition for a number of days.
Propagation is a numbers game. Be prepared that all your cuttings won't "take". Keep a journal so you can celebrate your success and learn from your mistakes. The garden should be a place of joy, so propagate if it's fun for you - if it's not your thing no biggie.