If you’re interested in how to propagate asters, you have three options to choose from. Unlike other plants with limited propagation methods, asters can grow either from seeds, cuttings, or divisions. VArious propagation methods put you at an advantage because you can choose the convenient technique for you.
While asters tolerate challenging conditions, you might find it advantageous to propagate them in the greenhouse. Starting plants in the greenhouse will put gardeners in the UK at ease because their young and fragile plants will be safe from unpredictable climate. So regardless of the method you choose to root asters, it’s good to consider the polytunnel to prevent potential problems as they establish themselves.
How To Propagate Asters Successfully
Option #1. Seeds
Unlike other perennials, you can grow asters from seeds. You can collect them from your existing plants, but you can also let your aster plants self-seed. In the British garden, these seeds are very similar to a dandelion seedhead that will aid in reproduction success.
According to the University of Florida, it takes 20 to 30 days for the aster seeds to germinate. However, starting them indoors, such as the greenhouse, can cut this into half and sprout at only 15 days. Regardless, the emphasis is necessary that these periods will only be possible if you correctly plant aster seeds.
You want to use a sterile and moist potting mix in seedling pots and sow two seeds per pot at ⅛ inches deep. After planting, mist to help with establishment and cover the pot with plastic to skip watering pots themselves. Do note that you still need to check the medium’s moisture and mist if necessary regularly.
You can remove the plastic cover once the seeds sprouts, then relocate the pots to somewhere that receives sun all day. As they grow, thin the asters with scissors and transplant the most vigorous ones after the frost has passed. However, you can also continue developing the asters indoors if the outdoor conditions are too challenging.
Option #2. Cuttings
While using seeds to propagate asters is simple and straightforward, using cuttings or divisions offer a significant advantage. You may want to produce an exact copy of a species, which will only be possible with these two methods. When you use seeds, there is no guarantee that the resulting plant will look the same as the parent plant due to cross-pollination or if the plant itself is a hybrid.
On the other hand, using cuttings or division is a reliable way to create clones of a parent plant that you like. So how does one propagate asters from cuttings? Depending on the variety, you can root them from softwood cuttings.
The ideal time to do this is in spring, and the process itself is not very different from how you propagate other flowering perennials from cuttings. What this means is that you’ll take a 5-inch section of a stem from a healthy parent plant. You’ll prepare this cutting by removing all the lower leaves until all remaining are 3 to 4 upper leaves.
Gardeners in the UK usually use sand or perlite as a medium and encourage rooting by covering the pot with a clear plastic bag. This technique helps with moisture retention, and the only management practices left to do are maintaining medium moisture, providing light, and eventual pinching when the cuttings root.
Option #3. Division
Another way to create aster clones is by propagating them from division. Propagating from the division is excellent if you have many mature asters that you can divide as they grow large enough every three years. When is the best time to divide asters?
It’s common to divide asters in early spring when you notice the flowers fading. The simplest way to divide a plant is to cut straight down at the centre to get two halves. Carefully work your shovel to lift each piece and remove all the loose soil from the roots.
Before planting, make sure to remove all the dead plant material so that you’ll be left with new shoots and roots with some soil. You can also take out the whole plant if you think this is a more comfortable method to divide asters. Now, how does one plant aster divisions?
It’s ideal to start indoors in a consistently moist potting medium. But if you wish to transplant directly in the UK garden, check first if the danger of frost has passed. In the UK garden, the divisions can have 18 inches of space among them, in holes that are slightly larger than their roots.
Do you wish to have asters or increase their number in your UK garden? You can learn how to propagate asters either via seeds, cuttings, or divisions. When choosing a method, perhaps the difference in using seeds is that the resulting asters will not look the same as their parent plants.
On the other hand, using cuttings and divisions will guarantee copies of your desired asters. The ideal time to propagate aster is in spring, and you can also let the plants self-seed. More so, you can either take 5-inch cuttings or divide a plant into two root sections for replanting for the other methods.
Regardless of which method you choose, perhaps a similar trend maintains the medium’s moisture and even covers the young plants with plastic. You can use a polytunnel for starting asters and then transplant outdoors after the danger of frost has passed.