Lilies will divide themselves in the soil and become crowded. This will cause the patch to produce fewer blooms. Having fewer blooms is a sign that it’s time to divide and transplant the patch.
One solution is to draw a circle around the plant using spray paint before the flowers fade. Alternately, mark the spot with a circle of stones, or insert plant markers into the soil (without damaging the bulb).
If you know your soil to be clay-heavy or have poor drainage, or if you observe puddles forming and disappearing rather slowly when it rains, you’ll need to improve drainage by digging in plenty of grit or compost. Alternately, consider raising the beds. Weed the soil at the new planting site and incorporate some organic matter into the soil. This organic matter can be compost or manure. Leave the bed to sit for a few weeks or months.
You should note that, while it’s better to transplant the bulbs when dormant in the fall, it probably won’t harm them to be moved in the late summer or winter. However, this can lead to a delay in flower production during the next season.
Leave the foliage on the plant until it withers away of its own accord. By mid summer, when the flowers emerge, there won’t be any foliage remaining. After the flower withers away the plant will go dormant. By the time the fall comes, none of the plants will be visible above ground and the plant should be dormant.
To divide the offsets, gently pry them off with your fingers.
You may now have more bulbs than you realized! It may not be worth keeping the smallest ones. However, if you have the patience to wait several years for them to mature, you might consider planting them amongst larger bulbs or at the back of a bed so you won’t notice a bare patch in the garden.
Store them in a cool dry place such as inside a paper bag in a shed or cool cupboard.
Place them so that they are sitting on handful of bulb compost and with the pointed end facing upwards. Fill in the hole with soil around the bulb and tap it down gently. Avoid pressing the dirt down with your feet. Water the area well.
