Propagate by Cuttings

Propagation by cuttings is sometimes considered a technique for houseplants. But for many garden and landscape plants, propagating by cuttings is the best method

root cutting by Midwest Gardening.jpg

We generally use division to propagate plants that grow in clumps. The division points are usually obvious, with separate rooted crowns. Division also extends the life of the matured plant. Division, or simple separation, is also easy and effective for clumps of bulbs or corms.

Propagation by cuttings makes sense for woody plants that cannot reasonably be divided. There are also herbaceous plants that do not like to be moved or dug up, and may struggle to thrive if dug up and divided. In that case propagation by cuttings also makes sense. Of course the cuttings method is fairly easy and can be used for virtually any plant. This is a great way to produce plants with little or no expense.

CUTTING TYPES:

  • Softwood Cuttings Herbaceous plant cuttings as well as fresh new growth on woody plants that are produced in spring or early summer. (When propagating hardwoods, be aware that the newest soft green growth may often rot before it will root.)

  • Greenwood Cuttings First year young stems of woody plants just beginning to mature in midsummer.

  • Semi Ripe/Semi Hardwood Cuttings Slightly matured stems that have become tough in midsummer to fall. The wood will be reasonably and and the leaves will be mature size.

  • Hardwood Cuttings Woody stems taken when dormant in late fall or winter.

PREPARE YOUR SUPPLIES:

  • Sharp clean knife or pruners

  • Rooting hormone, preferably with fungicide

  • Soil-less Potting mix

  • Potting containers

  • Cloche or clear plastic bag

TIPS FOR STEM CUTTING:

Select strong healthy plants for cuttings. The parent plant’s current natural vitality can affect rooting. Cuttings from a stressed, old, diseased or over fertilized plant may not root well. Avoid thin weak shoots as well as the thickest heavy shoots.

Clean your cutting tools before starting. Dip them in rubbing alcohol or one part bleach mixed to nine parts water between cutting plants to avoid transfer of disease that may be present.

Take your cuttings in the early morning if possible. The plant will be holding plenty of moisture early in the day. Be sure to take your cutting from a healthy portion of the plant that has no flowers or buds. If you must take a budding stem, remove every flower and bud that will sap all the energy needed for rooting from your cutting. Stem cutting should not be longer than 6 inches so as not to waste energy supporting a large cutting. They just don’t seem to root well if too long or if it does root, the plant will be long and lanky rather than compact.

Cut the stem just at/below a node where a leaf is attached. This is where roots will develop easiest, as well as where lower leaves are removed. Remove all leaves except the top two or three. Just a few are needed to create food by photosynthesis until the roots develop. Once cut, loosely wrap or cover the stem cuttings in moist paper towel to prevent drying out and sun exposure, especially important for softwood cuttings.

TIPS FOR GOOD ROOTING:

Rooting in water sometimes works well, especially for certain houseplants. But ideally a sterile, soil-less potting mixture will help the cutting grow a better root system. One part perlite and one part peat is a good rooting mix. Some plants require excellent drainage and a sand or perlite will be better to prevent the cuttings from rotting in too wet mix. Avoid vermiculite which compacts easily and holds moisture. Never use garden soil as it remains too wet and contains spores and soil bacteria that may harm the cutting before it can root.

Some plants, again often houseplants, root very easily. But some need some help or won’t root at all without the assistance of rooting hormone. To prevent contaminating your container of rooting hormone, put a small amount into a small cup or container to use so potential contaminants and moisture do not get into the whole container. Turn the cup on it’s side to allow you to roll the stem completely in the rooting hormone. Be sure to cover every node where leaves were removed. This is a primary place where roots will form. Lightly tap off any excess rooting hormone. Dispose of unused portion.

Difficult to root plants should be “wounded”. Strip away part of the hard outer bark layer with a sharp clean knife until fresh green is exposed. A one inch strip of exposed green at the bottom of the cutting is sufficient. Then apply rooting hormone as above.

TIPS FOR WOODY SHRUBS AND TREES:

Hardwood stem cuttings can be made with a straight cutting of newest, but dormant, stem growth. For shrubs and trees that are more difficult to root you can use a mallet or heel cutting. A Mallet cut includes a small section of old wood and a heel cut includes a large section of the old stem where the new lateral growth is attached.

SIMPLE PROCEDURE:

  • Fill containers with potting mix, sand, perlite, sphagnum moss or vermiculite and thoroughly moisten the mix. Tiny containers are fine to start the cuttings, or put more than one in larger containers.

  • Poke holes into the potting mix with a pencil to insert the cutting into. Creating a hole will prevent the rooting hormone from being removed if you push it into the soil. Make sure the hole is a bit large than the stem cutting.

  • Make a clean sharp cut of stem from healthy growth. Cutting should be at least 3” long.

  • Snip lower leaves off at the stem joint.

  • Dip stripped stem in rooting hormone to help it root quickly. If the rooting powder is not sticking to the stem, dip stem in water first and tap to remove excess water.

  • Place stem cuttings into prepared holes and lightly firm mixture up around stems. Be sure to insert the stem nearly up to the top leaves. More than one cutting can go into even a small pot for starting, just allow enough space for all leaves to get sunlight.

  • Water lightly to settle the potting mix around the cuttings.

  • Place a glass cloche or create a cloche with a jar or soda bottle over the pot to keep it humid. Or create a plastic tent with a clear plastic bag. Blow air into the bag to keep it from touching the cutting and seal it.

  • Place the covered cuttings where they will receive indirect light, avoid direct sun. Keep the potting mix moist, mist regularly until rooted.

Patience and careful checking is necessary now. Depending on the species, rooting may take 3 to 6 weeks at least. Stubborn rooters might even need a few months. Check the drainage holes for roots poking through beginning around 3 or 4 weeks. Don’t rush this, there is no hurry. If you get anxious a very gentle tug will tell you if roots are developing. If the cutting pulls right out it is way too early. Replant it and hopefully you have not ruined the success of that cutting. Success rate is rarely 100 percent anyway.

Once you can see that good roots have developed the cuttings are ready to be transferred singly to a larger pot - NOT to the garden yet! Prepare one pot per cutting with a standard potting mix. If you planted more than one in a pot, gently separate them to be replanted. Monitor the plants carefully for water and light. Diseased or ailing plants need to be removed to prevent disease or fungus from spreading. Remove dropped leaves. Allow the plant to develop a good root ball and a healthy plant that is forming strong new growth. Water with a very light solution of kelp or fish fertilizer.

Before replanting a strong bedding size plant to the garden, be sure you have hardened them off well. Slowly increasing exposure to sunlight and outdoor temperatures will make sure they are strong enough for the garden. Be sure there is ample time before frost for the plants to establish in the new garden home. If it is getting late in the season it might be a good idea to plant them in a sheltered “nursery” spot in the garden until next season.

Check the next page for a list of best plants to propagate by cuttings and suggested methods.

Sharon DwyerComment