Cuttings from many annual plants will keep over winter, sprout roots, and be ready for planting in spring. You may place them in pots or cups without drainage filled with moist perlite or vermiculite. Locate them at first in bright light, away from the sun. Move later to an area where they receive morning sun.
There are many plants that can be propagated during winter. We often take cuttings during winter as it's a quiet time in the nursery. Most people may assume that it's simply too cold to take cuttings during the winter months, however there are quite a lot of plant species where winter propagation is the perfect time.
Propagating plants in winter does take a bit longer than in the summer, two to four months for roots to develop, but it's a great way to get free plants from winter prunings. Providing bottom heat will speed things up a bit, but isn't necessary.
“Grafting, budding, and plant propagation can be done on many types of plants during the winter, not just hardwoods.” High humidity and moisture are important during the post-cut and post-grafting periods.
It will slow transpiration while the necessary components are used at the root sites to build a new root structure. Keep the atmosphere around the cutting warm (not hot), keep the humidity relatively high (>90%), and keep the root zone temperature warm (at about 25°C).
Especially with cuttings, it's often desirable to have a cooler (5 to 10° F) air temperature than root tempera- ture, which allows the roots to grow more quickly than the shoots.
Warm growing medium temperatures accelerate cell division which leads to faster callusing, root initial development and subsequent root growth. It also speeds up the dry-down rate of the growing medium, which also helps encourage better rooting. The best way to warm the growing medium is through bottom heat.
It is best to harvest cuttings in early spring and plant immediately but if this is not possible, cuttings can be stored safely for about 4 months. Store cuttings in a cool, dark, and moist place. Do NOT store in a wet area as this will promote root growth and weaken the cutting.
Sprinkle rooting hormone powder on a saucer. Dip the cutting in the powder, which will encourage root growth once it's planted.
Some plants will root in water, but cuttings will develop a better root system when rooted in a soil-less potting mix. Sand or perlite can also be used, especially for cuttings that need good drainage and may rot if kept too wet.
The problem is if the cutting is too long the plant is more likely to wilt and stress. If the cutting is wilting it's far more likely to fail and not generate roots. Smaller cuttings will lead to better success rates and overall better outcomes for you and your cuttings.
Technically, you can transfer your cuttings to soil at any time. In fact, you can actually propagate directly into soil, however, it's much harder to do within your home. When you propagate in soil, you have to keep a good balance of soil moisture, air flow, and humidity.
Hardwood cuttings provide an easy and reliable method of propagating a range of deciduous climbers, trees and shrubs, and as bonus, they are taken from mid-autumn until late winter when more time is usually available to the gardener.
In general, the rooting medium should be sterile, low in fertility, drain well enough to provide oxygen, and retain enough moisture to prevent water stress.
Most softwood cuttings are taken in spring and early summer, from the tender new growth of the season. If potted by mid-summer they will develop sufficient roots to survive the winter, otherwise pot up in the following spring.
The sooner you can get your cuttings into a more normal environment with air flow and no dome, the better off they'll be. After about a week, remove the dome and monitor your cuttings to see if they begin to wilt. If they do, they're not ready to go dome-less, so try again in 1-2 days.
Try to wait until at least 50% of the cuttings have good rooting before potting them up; however, for some hard-to-root species, you may be lucky with only 10% to 20% success.
When to take cuttings. The best time to take softwood cuttings is from mid-spring to early summer. Hardwood cuttings are taken later in the year, from mid-autumn to mid-winter.
Media is usually kept at 72-77° F while air temperature is maintained at 68-73° F. If bottom heat is not used, air temperature should be maintained between 77 and 80° F. Maintaining air temperatures lower than medium temperatures retards shoot growth while promoting root development. Excessive heat can damage cuttings.
Bottom heat is essential for root initiation since the growing media temperature should be maintained at a minimum of 68 to 72F (20 to 22C), depending on species.
To use your homemade rooting hormone, dip the bottom of the cutting in the solution before “sticking” the cutting in rooting medium. Using apple cider vinegar as rooting hormone is a great way to give your cuttings that extra jump they need to grow roots.
Give cuttings bright light but not sun. Keep soil moist but not wet. The cuttings should root within three weeks. Admit air gradually to wean the cuttings from their humid environment, then pot singly before outdoor planting.
You will know the plant has rooted if after a month or two it is still alive, the leaves haven't fallen off, and new growth is apparent. After a few weeks, you can gently tug at the cutting and if it sticks, you're OK.