Alliums produce spectacular globe flowers, but once these flowers have faded what do you do with your allium plants? Let’s have a look and find out.
So, What Do You Do With Alliums After Flowering?
This is important for strong growth next year, so don’t be tempted to tidy up your alliums, even though they can look quite messy.
The leaves will quickly go droopy and yellow but you need to leave them like this and resist the urge to tidy them up. If possible grow them in borders where they will be less visible or in pots where you can move them out of sight.
Dividing Alliums
Ideally, Alliums need splitting and dividing roughly every 3 years. While splitting plants can be a daunting task for gardeners with alliums it is actually really simple.
This is a job best done in Autumn once the foliage has fully died off and gone brown.
Lift the plant using a spade or trowel, digging carefully around the plant. Once lifted shake as much soil off as possible and then have a good look at the roots.
You should notice lots of separate bulbs rather than it being one solid mass. This is what makes dividing alliums much simpler than other plants.
Gently prise these individual bulbs apart before planting them on in new spots, also remember to leave a few bulbs in the original spot. It sounds simple but this is a really easy step to forget!
Overwintering Alliums
Once your alliums have finished flowering and the leaves have died off it will be time to turn your attention to protecting the plants overwinter.
For most alliums this is straightforward and they can be left in the ground with little risk. A mulch of straw, compost or bark is a good idea to add a little extra protection but it isn’t strictly needed.
Where you might need to do something is with Alliums that are grown in pots. The soil in pots is much more likely to freeze solid than ground soil is.
For this reason, you need to protect pot-grown alliums over winter. You can move them to a frost-free spot or simply cover them in some plant fleecing.
Harvesting Seeds From Alliums
You can harvest the seeds from your alliums once they have finished flowering. This will allow you to grow new plants from seed rather than growing them from bulbs.
To harvest allium seeds you need to wait until they have just started to brown. But you don’t want to wait too long as they quickly open up and fall from the flower head to spread themselves all over your garden.
If the seed pods are still a bright green then it is too early.
If they look like the above photo then it is still too early.
To harvest the seeds just snip the head off and then place the full thing into a large paper bag or envelope and leave it in a nice dry spot until they are ready to plant.
When you come to pull the head out of the bag next spring just give it a good shake as you are doing it in order to shake all of the seeds off and into your bag.