How do I plant/harvest Freesia seeds?
During a long life which has included much interest in Gardening and plants I have never heard of ordinary gardeners using freesia seed. These plants are usually propagated by using the corms. Plant breeders use the seeds to develop the plants but using seeds is an unpredictable and more difficult way of growing more plants. I would open the pods to make sure you have some seed, I’ll be surprised if there is any if you picked the flowerheads. If there is any then sprinkle it on a seed-compost and cover lightly with sand. Keep moist and wait. You’ll have to wait several years to get plants big enough to flower.