To collect agapanthus seeds, wait for the flower heads to dry and turn brown, with capsules starting to split open, then cut the stalk and shake the black seeds out into a paper bag or bowl, collecting them when they're fully ripe on the plant for the best results. You can protect the heads with a bag on the plant to catch seeds as they burst, or let them dry indoors after cutting.
Collect seed when the seedhead is becoming brown and the capsules are starting to burst. If the weather is turning cold you can collect seed prematurely and store the whole seedhead in a paper bag, but it's preferable to let the seed ripen on the plant.
Allow a few faded flowers to form seed pods in autumn to prolong interest and cut back to base when they have gone over.
The seeds which are flat and black are dispersed when the capsule splits and at this point it should be collected. Fortunately, unless there is a strong wind the dispersal is not immediate, and there should be ample time to collect it before it falls to the ground.
One of the most common questions gardeners ask about growing agapanthus, is whether they should be cut back after flowering. The answer is a resounding yes. Pruning agapanthus dead heads at the base after they've flowered helps promote healthier plants and more abundant future blooms.
I'm less fond of my Agapanthus: they too self-seed everywhere and frankly have become a bit of a weed. I never would have thought this possible. I remember coveting these plants with their big showy blue or white globes of flowers as a child.
The upright stems with their whorls of spent flowers look particularly pleasing with a dusting of frost on them. Otherwise, agapanthus heads can be saved and dried until those dark winter nights when you might want to spray them for Christmas decoration.
Cut the stems down a bit and stack somewhere dry and warm. If I am doing this just for myself I often just put the stems in a large vase. Leave for a couple of weeks until it is easy to peel back the outer casings from the top. Carefully remove both sides from the seed casing and brush off the seeds.
Collecting seeds with unstable genes
This is why it's wise to avoid saving seeds from hybrid varieties, regardless of how much you loved the crop. Open pollinated varieties of many crops can cross with one another, too, so it's important to isolate plants from which you plan to collect seeds.
If you are collecting seeds from non-fruiting plants, gather the seeds on a dry day. Spread the seeds on newspapers, in a cardboard box, or in an old telephone directory, and allow them to dry between one and three weeks. Often seeds need to be separated from the chaff (the seed casings and debris).
Collecting seed
Bulb rot and root rot are both agapanthus problems that start underground. They show themselves above ground in yellow, wilted leaves and sometimes stunted plants. If you dig the plants up, you'll find the roots or bulb decayed and discolored. If one of your plants is infected with root or bulb rot, it can't be saved.
Agapanthus can be easily propagated through division (dividing up the clump) in autumn by carefully digging it up from the ground or removing it from the pot. Gently shake off some of the soil or potting mix so that you can see the roots and the individual plants.
The 3-5-8 rule in floral design is a guideline for creating balanced arrangements, typically using 3 focal flowers, 5 stems of greenery, and 8 stems of filler flowers, inspired by the Fibonacci sequence to create natural harmony and visual appeal by grouping elements into distinct sizes. This rule helps DIYers build cohesive bouquets that aren't too sparse or heavy, providing structure with fewer "hero" blooms, supporting volume with greenery, and adding lushness with smaller accent flowers.
Seeds are meant to germinate when they're moist, and hibernate when they're dry. That's why it's important to dry your seeds after you harvest them. Open-air drying is the best way, and there are several methods for creating just the right conditions for perfect seed drying, using ordinary household items.
The general rule of thumb is that you should deadhead flowers as soon as they're spent, and this is also the case with agapanthus. As agapanthus is one of the best bulbs to plant in February, most agapanthus plants will flower for around six weeks from mid-summer to early autumn.
Here's how: Once you have removed the agapanthus seed pods from the plant, place them in a paper bag and store them in a dry location until the pods split open. Remove the seeds from the split pods. Place the seeds in a sealed container and store them in a cool, dry place until spring.
Most authorities confirm that agapanthus is very difficult to get rid of, even with powerful sprays. Common recommendations are for glyphosate, metsulfuron-methyl (MSF600) and triclopyr (Triclo). Our experience is that they all will work, but that glyphosate and MSF600 are more effective at some times than at others.
(If you propagate from seed you're unlikely to end up with exactly the same flowers, as the plant may have cross pollinated with other varieties.) The best time to divide agapanthus is late March to April, before the flowering season.
Agapanthus do well in both pots and the ground, with the best choice depending on your goals: pots offer control for limited space, frost protection (by moving indoors), and preventing spread, while the ground allows them to naturalize and form large clumps for a bigger impact, though they need more effort to manage if they become invasive. Pots are great for patios, balconies, and colder climates, while in-ground planting suits sunny garden beds.