I planted some bulbs last fall and am admiring the flowering results. Can you offer some tips on how to best care for them now?
— Emily Spiewak, Niles
The bulbs flowering in my garden at home are putting on a great show as are the ones at the Garden. Spring-flowering bulbs are very effective for bringing early color into the garden. Bulbs do not require much maintenance. They prefer to be planted in an area that is moist in spring and fall and dry in summer. Most bulbs will not perform well in beds that are consistently moist or watered heavily throughout the summer. An important part of being successful with bulbs, like with other plants, is choosing the correct ones for the growing conditions in your garden. Take photos of your garden beds now to guide you in selecting and ordering bulbs for planting this fall. The photos will show you where to plant new bulbs in the fall and help you decide which to choose. Plant daffodils, hyacinths and ornamental onions if you have rabbits or deer browsing in your garden. Tulips and crocuses tend to be eaten quickly as they emerge from the ground in spring. Spray your bulbs with a repellent if you are having issues with animals. Rotate different repellants and reapply after rain.
There is a strong temptation to cut back bulb foliage too soon as the weather warms and the foliage looks increasingly worse. It is better to wait until bulb foliage has gone dormant before cutting it back. The leaves will turn yellow to brown, and once the leaves have all turned yellow, it is OK to cut them back. The bulbs need their leaves to photosynthesize and make food that is then stored to produce foliage and flowers next year. Cutting foliage back too soon can reduce the vigor of the bulbs and their flowering the next year. Tying up the leaves, bending them over and braiding the leaves are not good practices, as they reduce the leaf surface for photosynthesis. If you have planted bulbs in a lawn, hold off on mowing the lawn in these areas to give the bulbs time to go dormant. You will probably need to cut the grass before the bulbs are completely dormant, so set the mower at the highest setting to save as much of the foliage as possible.
I do not fertilize my bulbs, but I leave the leaves on my garden beds for natural nutrient recycling. Your bulbs will get adequate fertilizer if you fertilize your garden beds. Phosphorus is often recommended for bulbs, but this nutrient does not readily move through the soil, so surface applications of it do little good for the plants in your garden. Many garden soils already have adequate levels of phosphorus for plants to perform well in this region. Test your soil if you want to know for sure. If an established patch of bulbs starts to bloom less and less or begins blooming sparsely, the bulbs may have become overcrowded or the planting site may be too shady. That’s the signal to dig and divide or move bulbs to another location. The first step is to lift the bulbs from the ground, being careful to dig the bulbs and not pull them up by the foliage. Take care when digging that you don’t damage the bulbs themselves. Start digging a few inches away from the plants and wait until the bulbs are loosened. The best time to move or divide bulbs is when the foliage has gone dormant (meaning the leaves have finished producing food for next year’s flowers) and you can still see their location.
To divide bulbs, carefully pull the small bulbs from the base of the plant to increase plant numbers and gently separate them so that they can be planted with more spacing in their new location. The larger the small offset bulbs are, the sooner they will flower. Check the original bulb for firmness. If it appears to be in good health, go ahead and replant it; you may still get several years of flowering. If it appears shriveled or damaged, toss it.
