Learning the Art and Science of Plant Propagation

— Written By N.C. Cooperative Extension

Article by Gates County Extension Master Gardener, Cynthia Wagoner

This time of the year, gardeners look forward to getting ready for fall, planting a fall garden, digging up tender bulbs, dividing plants and taking cuttings and seeds for new plants for future use and to share with neighbors and friends. This article identifies various methods for plant reproduction for the homeowner.

Important Conditions
1. Sanitation
2. Moisture levels
3. Temperature levels.

To propagate rosemary:  Take some cuttings in the summertime, strip the bottom of the cutting a few inches of leaves, stick  in moist soil, and place in shade. No rooting hormone needed.

Cuttings:

When taking cuttings there are several rules for success: Choose healthy plants that are not diseased or wilted from under watering; with good nutrition and light. When preparing the area, make sure that good sanitation is followed. Choose potting soil that is free from pests and disinfect the containers, greenhouse, benches, soil bins and tools. Washing with 10% bleach is effective when disinfecting.

Cuttings for propagation:

Stem cuttings: (1) herbaceous, for woody plants — firmness of wood and time of year. (2) Softwood, late spring/early summer. (3) Semi-hardwood, fall mostly or late summer, starts to firm up. (4) Hardwood, winter. This is

How to take a stem cutting:
1. Use a sharp knife or pruners to cut a piece at least 3 inches long from the plant. Cut at an angle. Remove any flowers or fruits.
2. Remove lower leaves.
3. Cut the leaves in half. Prevents transpiring out of the leaves. Race against time – want to grow roots and not send energy to leaves.
4. Apply rooting hormone. Most plants will benefit from using rooting hormones. IAA or IBA should be in the active ingredients list. Two forms: Powder form, which is inexpensive and easy to root. For more difficult to root species – use liquid rooting hormone.
6. Stick into media with node in contact with or just below substrate surface.
Needs high humidity situation – reducing water loss. Pot method – put cutting in pot and simply put a plastic bag over the top. Don’t need greenhouse for home propagation. Close to 100% humidity as you can.

Leaf cuttings:
Leaf cuttings work well with African Violets and begonias, and commonly used with houseplants. This method will not work with woody plants.

Root cuttings:
Small piece of root, stick in media, no hormones needed.

Seeds:

The advantages of seed propagation is: (1) Less technical, (2) easily shipped and (3) genetic diversity. To make sure your seed is viable (alive and capable of germination), do the following test: Put all seed in a jar of water, and the ones that float to the top are not viable. There is “nothing in there”.

Seed germination: Media needs to be moist, 50 to 70 degrees in temperature, oxygen circulation, light – (sometimes – depends on species).

Common questions:

1. How deep should you plant your seed: A general rule of thumb is to plant the seed 1 1/2 deep of the diameter of the seed. Really important not to plant your seeds too deep. There is not enough stored energy in seed to make it sprout.

2. How far apart do I space the seeds? Do not space too closely together. Check seed packaging. When planted too closely together, the seeds compete for light, and become tall and leggy, weak seedings.

3. When is it time to transplant seedlings? General rule when the first set of true leaves emerge, it is time to transplant into their next location.
The most important thing to remember is to be very gentle. You never want to pull from the top; scoop from bottom – very important – take your time very carefully plant them into their new container.

To start a new grape plant is easy!  Simply take one of the long vines in the summertime, strip some leaves, place that part in a pot with soil (covering the vine with soil), water (keep moist), and place a weight on top!

Layering:

Layering is simply getting the cutting to root while still attached to the host plant. While roots are forming, it is getting water and energy from parent plant.

Air layering
1. Girdle stem, scrape outer layer of bark all the way around the stem. (Go through the green color, down to the cream color.)
2. Cover with moist media.
3. Cover with plastic – roots will form – takes three months
4. Then cut from parent plant.

Example of gladiolus corm with cormlets.

TENDER BULBS: Tender bulbs are defined as plants which have fleshy storage structures such as bulbs, corms, tubers and roots which die when exposed to cold winter temperatures if not brought indoors. Special protection is required involving digging up and bringing them into a warmer area for storage through the winter months. This can be done after the foliage dries back or is killed by the fall frost. Use caution when digging as one does not want to damage the bulb/corms or tubers. Loosen the soil on all sides with spade so roots are not cut off unnecessarily. Diseases can enter through cuts easily and cause rotting. The next step is to “cure” the bulb/corm or tuber. This can be done in about 2 to 3 weeks, depending on the temperature and type in a sheltered location away from direct sunlight. With gladiolus, the old corm and the little cormels should be removed. (See photo of gladiolus corm and cormels after being dug.) After cured, place in paper bag and label. Remember to check stored bulbs periodically to make sure they are not rotting and remove any damaged material immediately. Glads should be stored over the winter in a location providing temperatures of 35 to 40 degrees.

Updated on Sep 12, 2014
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