Did you know that there are over 400 species of geraniums?
It’s not unusual to find a variety you like, want to grow the exact same again, and not be entirely certain you’ll find the same type at your local nursery, or even an online seed store.
If you want to grow the exact same species, you need to know how to collect geranium seeds.
It does take patience because you need them to be ripe.
Timing is critical because once ripened, there’s a very short window of time to harvest seeds before the capsule opens and the seeds inside are lost to the slightest of a breeze.
How to collect geranium seeds?
At the end of the season, stop deadheading geraniums to allow them to go to seed. Flowers need to dry completely for seed pods to form. Once they’re ripe, they open, and the seeds will catapult. Place mesh bags over flowers and it’ll catch the seeds from ripened pods before they get blown away.
Encouraging geraniums to seed
Geraniums only put out seed pods when the flower is completely dry.
You need to stop deadheading geraniums for that to happen.
Naturally, if you want a lot of seeds, you’ll need to have a lot of dying flowers on your plant. That’s not a pretty sight.
It doesn’t take much to grow a new plant from seed. It is sufficient to leave all your seed harvesting until fall so that only the last blooms are left to go to seed.
Alternatively, if you’d rather collect more seeds throughout the season, leave the odd one or two flowers on the plant to go to seed, and deadhead others in more prime locations where you’d want more blooms.
For border plants, or growing geraniums in a container against a wall or fence like bougainvillea, the front flowers could be deadheaded and one or two blooms left on the less visible part of the plant to go to seed.
Keep in mind that your blooms won’t be as big and bright if you’re forcing the plant to focus energy on blooming and seeding at the same time.
The best practice is to choose which one are you going to prioritize: the seeds or the blooms.
Seed harvesting is best left until fall and deadheading throughout the season to prevent seedpods from forming.
This keeps the energy focused entirely on blooming during the season.
By the end of the season, when you don’t expect decent blooms, that’s when you leave the flowers on a geranium and let them all go to seed.
The seed pod on geraniums are like long thin spikes that develop out of dying flowers. The flowers need to be exposed to sunlight but left to dry too.
However, if you think the thought of geranium seeding’s a hassle for you, then you can try learning how to grow them through cuttings instead. Maybe you can try reading on how to prune geraniums for a start.
Catching geranium seeds
A unique characteristic of the seed capsules on geraniums is the cranesbill shape.
When the pod opens, seeds are catapulted into the air. Think of it as an integrated survival instinct to make sure the seeds survive.
The seeds don’t fall to the ground, but instead, get dispersed by the wind.
To catch the seeds, you need to cover the pod with a thin mesh bag before they ripen.
Light needs to reach it, but it still needs to dehydrate. When it’s dry, it will open, and once it’s open, it needs that mesh bag to catch the seeds, or they’ll all be lost to the wind.
They are tiny so to teeniest of breezes will carry them away.
The best time to cover geranium seed pods
As soon as seed pods develop on the tips of dehydrating flowerheads is when to cover them with a fine mesh bag.
To spot them, you need to look closely for them.
The initial seed pods start out as a green spike with five seed pods at the base of a flower spike. When they are green, they’re unripe and this is when to cover them with a mesh bag.
Ripe seed pods that are ready to open are dark green to black – both the spiky part above the flower head and the pods attached at the base.
If you don’t get the seed pods covered before they ripen, you’ll likely lose the seeds to the wind.
When the pods open, they branch out from the bottom up, releasing the seeds as they do.
That’s why geraniums have a reputation for having spring-loaded seed pods.
There is a chance one or two seeds could remain attached to the pod, however, they are more likely to be catapulted into the air.
As soon as you see green spikes with up to five seed pods form at the base of a flower on a geranium, that’s when to cover it with a mesh bag to catch the seeds before it ripens.
Once ripe, the seed pods can spring open anytime.
If you don’t have the mesh sacks (or nylon stockings to make a DIY mesh bag) you can cut away ripe seed pods, put them in an envelope or paper bag and leave them to open in their own time.
Ripe seed pods are best removed using a pair of small scissors rather than pulling them off.
Pulling the seed pods rather than cutting runs the risks of it springing open, firing the seeds into the air before you get a chance to catch them.
Frequently Asked Questions related to Collecting Geranium Seeds
How many seeds do I need to start a new plant?
You’ll need to sow two to three seeds per pot for each new plant you want to grow. This should be done indoors from early January for summer blooms. It takes up to 16 weeks for geraniums to bloom when grown from seed.
Is it better to grow geraniums from seed, or should I grow from cuttings?
Either method works, but both have different outcomes. Geraniums grown from seed have better resistance to disease, and produce more flowers, although they’re often smaller than the flowers on geraniums grown from cuttings. Propagating geranium cuttings can get spring blooms. From seed, geraniums won’t bloom until summer.
Taking care of houseplants and gardening are my greatest passions. I am transforming my apartment into an urban jungle and am growing veggies in my indoor and outdoor garden year-round.