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A freesia corm is a small teardrop, usually well under an inch (2 cm) across, with a papery brown tunic, a flat scarred base and a distinct point at the top. Unlike a crocus or a tulip there is rarely any doubt which way up it goes: the point is the shoot. Set the corms upright, roughly two inches (5 cm) deep and two inches (5 cm) apart. Deeper than that gains you nothing, because the stems are thin and the extra soil simply delays emergence.
In a pot, close spacing is an advantage rather than a compromise. Ten to twelve corms in a six inch (15 cm) pot produce a mass of stems that lean on each other and look intentional, while three corms in the same pot produce three sprawling stems and a lot of bare compost. Freesia is one of the few bulbs where crowding genuinely improves the result.
Use a free-draining mix. Ordinary potting mix with about a third by volume of coarse grit or perlite is right. The corms sit in that mix for months, part of it while barely growing, and a heavy water-retentive compost is how most of them are lost before they ever show a leaf.
| Item | In pots | In open ground |
|---|---|---|
| Depth | 2 in (5 cm) | 2-3 in (5-8 cm) |
| Spacing | 2 in (5 cm), deliberately crowded | 3 in (8 cm) in a block, not a line |
| Mix or soil | Compost plus one third grit | Sandy or gritty, never a wet clay pocket |
| Container size | 6 in (15 cm) pot for 10-12 corms | Not applicable |
| First watering | One thorough soak, then wait | One soak if the soil is dry |
Cool air is not optional, it is the whole method
Freesia sets its flower buds only while the nights are cool. Below about 60F (15C) at night, and ideally nearer 50F (10C), the corm builds a flower spike inside the shoot. Above that, it builds leaves and keeps building leaves. A corm started on a warm windowsill or in a heated room will come up fast, look promising for a month, and then simply go on producing thin foliage until it exhausts itself. This is the single most common way freesia disappoints people, and once the warm start has happened there is no correcting it later.
So the planting decision is really a placement decision. Plant when you can give the pot eight to ten weeks of cool nights: an unheated greenhouse, a cold frame, a porch, a sheltered spot outdoors in a mild climate, or a bright unheated room. Daytime warmth is fine and even helpful; it is the night temperature that does the work.
In climates with cold winters that means planting in late winter or early spring for early summer flowers, keeping the pot cool but frost-free. In mild climates with wet cool winters and dry summers, autumn planting outdoors gives the natural cycle and the best flowers, because the whole growth period happens through cool weather.
If you can only offer a heated indoor room, do not plant. Hold the corms dry and cool and wait for a season when you can give them cool nights. A warm start wastes both the corm and the year.
Getting them into growth without rotting them
The period between planting and the first leaf is when corms are lost. They need moisture to start rooting but they have almost no leaf area to draw water off, so a pot kept constantly wet turns the corms soft. Water thoroughly once after planting, then let the top inch (2.5 cm) dry before watering again, and keep to that rhythm until shoots are two or three inches (5-8 cm) high. From then on the plant is drawing hard and you can water freely.
- Soak once, then hold back Water the pot until it runs from the base, let it drain completely, and do not water again until the surface has dried and the pot feels appreciably lighter. Expect this to take a week or more in cool conditions.
- Keep it bright from day one Freesia shoots stretch badly in dim light and never recover. Put the pot in the brightest cool place you have before anything emerges, not after. Full sun through glass in cool weather is not too much.
- Watch for emergence and start counting Shoots usually break the surface two to four weeks after planting depending on temperature. That date is the start of the clock: flowering typically follows ten to fourteen weeks later.
- Put the supports in now Push thin twigs or a ring of short split canes into the pot while the shoots are still small. Doing it at this stage means the stems grow up through the support instead of being tied to it later, which always looks like a repair.
Write down the start, not just the flowering
The date you planted, the date shoots appeared, and roughly where the pot stood each of those weeks are the three notes that make next year better. Freesia results vary enormously with the temperature of the first two months, and the only way to tell a good position from a bad one is to have last year's dates to compare. Record the coldest place you were willing to use and whether it flowered; if it did, that is your spot permanently.
Also note the number of corms per pot and how the display looked. Almost everyone under-plants the first year and then has to guess how many more to add. A written count removes the guessing.