Under the right conditions, Irish Moss (Sagina subulata) is a real pro at spreading all on its own. But if you want to take the reins and start a new patch yourself, you can definitely go the DIY route with seeds. While it takes a little patience, it’s usually very successful as long as you keep a few specific tips in mind.
Irish Moss Spreads Naturally
If you’ve picked the perfect spot for your Irish Moss, the plant will typically handle the expansion for you. It spreads naturally through self-seeding and by sending out tiny runners. This is how it maintains that lush, dense “green carpet” look we all love without much help from us.
Getting Your Hands on Seeds
Let’s talk about the seeds for a second—they are absolutely tiny! To give you an idea, it takes about 5,000 individual seeds to weigh just 0.10 grams. If you want to start a new patch, you have two options:
- Harvest them yourself from existing plants.
- Buy a packet at your local garden center.
If you decide to collect seeds from your own plants after they finish blooming, you’ll need a steady hand and a sharp eye. Because they’re so microscopic, they are incredibly easy to lose.
Honestly? Most gardeners prefer buying them. It saves you the headache of trying to catch those tiny specks, and you know exactly what you’re getting.
How to Sow Irish Moss Seeds
Once you have your seeds, it’s not just about where you plant them, but how. Here’s what you need to know to make sure those little guys actually sprout.
When to Plant
The best time to get your seeds in the ground is during March or April. I usually recommend sowing them directly into the garden where you want them to grow. While you *could* start them indoors in seed trays and transplant them later, direct sowing is much easier and less stressful for the plants.
The Sowing Process
For the best results, keep these three rules in mind:
- Don’t bury them: Irish Moss seeds need light to germinate. Just press them gently into the soil; don’t cover them with a thick layer of dirt.
- Stay hydrated: Keep the soil consistently moist (but not soggy).
- Watch for intruders: Keep the area weeded. You don’t want aggressive weeds crowding out your tiny moss seedlings before they have a chance to establish.
Pro Tip: The Sand Trick
Since the seeds are so fine and hard to handle, here’s a little trick: mix them with a bit of quartz sand before sowing. The sand gives the seeds some “bulk,” making them much easier to grip and helping you spread them evenly across the ground.