What are all the ways I can propagate English holly?
Great question! There are two popular methods for propagating English holly (Ilex aquifolium). The first is to propagate by germinating and planting seeds. This process can take up to 18 months! Growing from seed also doesn’t guarantee that your new holly will look the same as your parent plant. In order to replicate the same coloring and shape, it is suggested that you propagate from cuttings.
To germinate from seed, follow these steps:
1. Fall is a good time to propagate from seed, as that is when the seeds are ripe
2. Collect holly berries
3. Clean the pulpy coat off of berries, leaving the naked seed
4. Scarify the seeds (aka, nick the seed coat using something like a nail file)
5. Some sources suggest following this with a warm stratification and then a cold stratification—or a warm and then cold period. You can do this by first running the seeds under warm water, and then cold water
6. Fill weather-resistant flats over half full with potting medium
7. Lay seeds on top
8. Cover with one more inch of medium
9. Place flats outside through winter, or in a cold frame
10. After two winters, the seedlings can be planted in their permanent positions
The other option is to propagate from cuttings. If you are trying to propagate a cultivar or a variegated variety, this method may work better for your purposes.
1. The best time to take cuttings is late summer, or early fall
2. Take a cutting from the parent plant (best results will be a cutting that includes a growing tip, cut on soft wood)
3. Cut a quarter inch below a leaf node for best results
4. Dip the cut end into water, and then into a rooting hormone. There are many commercial rooting hormones on the market. To make your own organic hormone, you can make a willow tea.
5. Plant the cutting in a full flat of potting medium
6. Place the flat in a shaded position in a cold frame
7. After 12 months these cuttings may be potted up, and can be layered the following October (after at least 12 months)
8. Transplanting should take place after two years
Note that Illex are diecious, meaning that they have separate male and female plants. In order to get showy red berries, you will need a male and female plant—female plants produce berries, but to make berries, a male plant is also needed. Illex also don't like to be transplated, so after your seedlings or cuttings are large enough to plant, try to place them in a permanent location when you put them in the ground.
NYBG Plant Information