The care information provided in this section represents the kind of practical advice is available for all the plants in this web site if you subscribe to the monthly customized newsletter Yardener’s Advisor.
Ideally, bulb beds should get about 1 inch of water a week from rain or from a watering system in the fall and spring when they are growing roots and pushing flowers. If your corms haven't gotten 1 inch of water during the week from rainfall, check soil moisture under the mulch to see if you need to water. Crocuses do not need much water while they're flowering, or over the summer once their foliage has withered and they are dormant. For information on products see the file on Choosing Watering Equipment
Crocuses in soil that has lots of organic matter do not need routine fertilizing. However, in mediocre soil they do best if you feed them twice a year, in the early fall and again in the early spring just after they've popped out of the ground. Sprinkle about a tablespoon of all-purpose slow acting granular fertilizer or specially formulated bulb_fertilizer for each plant or a slight handful for each bunch.
Do NOT feed crocus immediately after flowering when the bulbs can least use the nutrients--that just encourages disease. Of the two feedings the fall feeding is the most important because it encourages strong root growth for next spring.
A 1 or 2 inch layer of organic material such as chopped leaves, shredded bark or wood chips, spread over the bulb bed as a mulch, controls weeds and conserves soil moisture. When they bloom, it keeps dirt from splashing up on the flowers. Rake fallen leaves off the bulb bed in late fall. They will mat and prevent water from reaching the bulbs during the winter. Use chopped or shredded ones as a mulch. For more information see the file on Using Mulch
Another good way to further protect bulbs during the winter is to lay evergreen boughs over the bulb beds as a mulch. See the files on Winter Protection For Plants and Plant Protection Supplies
Pruning or Grooming
After they bloom, crocus flowers flop over and disintegrate in the next rain. However, the foliage continues to grow a bit. Resist the temptation to cut back the foliage while it is still green. This may mean not mowing the lawn for a few weeks if you have planted crocuses in turf. The leaves need several weeks to soak up the sun and store energy for next season. Allow them to age and turn yellow and collapse, then clean them up or mow.
Unlike many bulb plants, crocuses do not require thinning. They can be left undisturbed in the ground for years. However, each year crocus corms produce smaller "cormlets" attached to the parent corm that you can harvest and replant to have more crocus plants.
If, after 3 or 4 years in a bed, crocus flowers become smaller, the plants weaker, it may be due to crowding of these little cormlets. This is a good time to dig up the clumps of corms after the foliage turns brown well into summer. Shake the soil off the roots and separate the cormlets from the parent corms. Discard the old shriveled parent corm and plant the cormlets, which will produce flowers in 1 or 2 years.