You have to water a flannel shrub differently than most popular flowering plants for balconies and patios. And there are also some things to consider when fertilizing.Flannel bushes regularly need a lot of water
The California flannel shrub (Fremontodendron californicum) takes the hearts of many hobby gardeners by storm. The reason for this is the summery, golden yellow bloom, which enchants us well into the summer. But as the saying goes: nothing comes from nothing. In order for the flannel shrub to flower vigorously, you must provide it with water and fertilizer.
Water the flannel bush properly
The flannel shrub is used to long-lasting dry periods in its natural home in California. You should imitate the rare rains in nature as closely as possible when watering. What does that mean specifically? Water relatively rarely, about every 14 to 18 days, and a little more vigorously. No moisture should be felt in the substrate several centimeters deep before the next time you give water.
Always pour directly onto the substrate and do not spray the leaves and flowers with water during the day. The drops of water concentrate the light from the sun so that superficial burns can easily occur.
Due to the rare abrupt pouring, however, you have an easy problem to solve. In tubs without functioning water drainage, waterlogging can occur, which can easily lead to root rot in flannel shrubs (more about this here). Therefore, choose a bucket with one or more drainage holes for your flannel shrub and pour gravel, pumice or expanded clay in front of the substrate. This coarse material acts as a drainage that directs the water down from the bucket. You can then simply throw away excess water that remains in the saucer for more than a day.
This is how flannel bushes are fertilized
Flannel shrubs are rather frugal in terms of nutrient consumption. A regularly renewed, sandy to loamy soil provides a large part of the necessary nutrients and you only need to fertilize moderately. A commercially available flowering plant fertilizer, which you add to the irrigation water, is best suited.
Never fertilize dry substrate with the fertilizer alone, as this can easily burn the roots with salt. It is even advisable to divide the watering process even when fertilizing. That means: First pour half of the usual amount with clear water and only then add the liquid fertilizer to the second half.
Water and fertilize the flannel bush during the winter hibernation
Outside the growing season from April to September, the fluid requirements of the flannel shrub decrease again and you can further increase the time intervals between watering. In principle, you do not need to fertilize the flannel shrub in the cold season.