How to Propagate New Plants with Stem Cuttings
The most common form of propagation is by growing plants from seeds, but because the seed's development can be affected by cross-pollination, there is always a possibility of variations in flower color or foliage that differ from the parent plant. On the other hand, cuttings and other forms of vegetative propagation will produce an identical clone of the parent. Not all species of plants can be propagated from cuttings. When propagating with cuttings, ALWAYS remember that plants have tops and bottoms!
ALWAYS strike your cuttings with the up end UP!
The Proper Propagating Environment
Keep in mind that when you are doing any type of plant propagation, that what you are doing is "plant surgery", and cleanliness is vital for success.
Always use a clean, sharp knife and sterile rooting medium for the best results.
Because they have no roots, your cuttings will need very high humidity, and will really benefit
if they are kept in a propagating case, terrarium, or in a miniature greenhouse.
Keep the tray in a warm (70°-75°), brightly lit area or preferably, under a grow light.
Bottom heat will speed up the process considerably.
Since your cuttings have no roots, the rooting medium should not contain any fertilizer.
Most gardeners have their own preferences and opinions as to the proportions of the components used,
but they almost always consist of one or more of the same basic ingredients.
Of course, propagating certain plants may require a specific mix.
- Clean, coarse, builders sand is often mixed 50/50 with peat moss. It is sometimes used alone as the rooting medium. Do not use fine sand or beach sand because it does not allow for sufficient aeration.
- Peat moss is a good, water retentive addition to your rooting medium, but it tends to add the acidity of the soil pH. It is usually the primary ingredient for most rooting mixes.
- Vermiculite is created when the mineral 'mica' has been heated to the point of expansion, like popcorn. A good addition to container potting mixes, vermiculite retains moisture and air within the soil.
- Perlite is another mineral, which has been expanded through a heating process and forms light granules. Perlite is a good addition to planting mixes, to promote moisture retention while allowing good drainage.
Softwood Tip Cuttings
Softwood cuttings or greenwood cuttings as they are sometimes called are taken in early spring from tips or basil shoots that are almost fully developed, but have not yet hardened.
Since young plant material roots the the most readily, there is a greater chance of success, but this type of cutting is the most vulnerable to moisture loss, they will need to be kept in a very humid environment, such as in a terrarium.
Using a sharp, clean knife or very sharp pruner, take a cutting 3 or 4 inches in length from the top growing tips or vigorous side shoots. The cut should be made at a slight angle, just below a node. Trim off any flower buds and the lower leaves from the cutting, leaving a stem with 3-4 leaves at the tip.
Dip the cut end into a rooting hormone such as Roottone® or Hormonex®.
Insert your cuttings into pre-poked holes in sterile moist sand, vermiculite or peat moss deep enough that it will support itself.
At least one stem node must be buried, but it is better if there are 2-3 nodes covered. Firm the rooting medium around the cutting. Keep the rooting medium evemly moist, but never soggy.
Create a mini-greenhouse over the rooting tray with poly film over a wire frame or use
an old aquarium covered with glass or plastic and place it in a bright warm spot.
Keep the cuttings at a minimum temperature of 72°. Warmer is better.
After the cuttings have rooted and show vigorous new growth they can be transplanted into individual pots or moved to the garden after all danger of frost has passed.
Dianthus, Geraniums, Fuchsias, and Chrysanthemums are some of the many plants that can be propagated with tip cuttings.
Basal Stem Cuttings
Basal stem cuttings are usually taken in the spring, immediately after the first leaves on healthy new shoots have opened.
Each cutting must include a small sliver of the parent plant's crown attached at the base.
Trim the lower leaves, dip the cutting in rooting hormone and strike into individual pots or flats. Since these shoots are already growing when you make the cutting, they will root very quickly.
This method of propagation works on a wide range of herbaceous perennials that produce clusters of new shoots at their base including Lupines, Bee Balm, some Chrysanthemums and some Delphiniums.
Semi-ripe cuttings are less likely to lose moisture through transpiration than softwood cuttings, so they don't require a highly humid environment.This type of cuttings are best when taken from mid to late summer from the current years growth and have become woody at the base, but are still soft and pliable at the tip. Take a 4"-8" cutting from the leader or a healthy side shoot, just below a node. Remove the very tip of the shoot as well as the bottom pair of leaves. Using a very sharp blade, remove a small sliver of bark from one side of the stem, near the bottom. Dip the end into rooting hormone before striking in individual pots and placing in a cold frame or a cool, bright spot in the house. Harden off well rooted cuttings gradually before moving them to the garden when all frost danger has passed.
Daphne, Hibiscus, Lavender and Oregon Grape are a few of the many shrubby plants that are propagated with semi-ripe cuttings.
Hardwood cuttings are taken from healthy, fully ripened growth from the current year. Hardwood cuttings are taken very late in the fall and throughout the winter months. Cut a pencil size stem from the plant, at a slight angle, just above the point where the current years growth meets the previous years growth. Remove any leaves from deciduous plants. With evergreen plants, remove all leaves from the bottom 2/3 of the cutting, and cut any large leaves in half. Cut the stem into 6" pieces, just below a bud or node. Using a very sharp blade, remove a small sliver of bark from one side of the stem, near the bottom. Dip the end into rooting hormone before striking in individual pots filled with rich garden soil or in 6" apart in a prepared trench near the garden. Strike the cuttings deep enough that only the top 2" of the cutting is exposed. Firm the soil well around each cutting.
Provide a heavy mulch over the winter months.
Butterfly Bushes, Forsythias, Currants and St. John's Wort
are among the plants that can be propagated with hardwood cuttings.