Time now to dig and divide iris and daylilies for continued bloom
Not only is this a good time to dig, divide and replant iris, but it is an excellent time to do the same with daylilies. This will provide the bed some order and give mature and entirely too-thick clumps of plants a better chance at blooming next year. It also provides the opportunity to renew depleted soil by adding amendments and fertilizer.
Although you can dig Hemerocallis, daylilies, even when they're blooming, it is best to wait until after the bloom or even later in the summer. If your daylilies are not blooming now and you've incorporated them into the iris garden (they're spectacular together, the daylilies blooming after the iris), you might as well dig them. Monsoonal rain will give them a boost and help them become established before frost.
For dividing bulbs, many people advocate early spring digging or dividing right before the first frost but, to my way of thinking, waiting that long may not leave enough time for a good strong root system to develop before winter.
Daylilies, like the iris, are dug with a digging fork. Dig the soil deeply to ensure you remove all the roots without breaking them off. The ground should be relatively dry and the fork should be used to go around the clump so it lifts easily. Shake off the loose dirt clods then trim the tops to about eight inches or so. Hose off the roots so you can see where to make the divisions.
To make a better showing when planted back, allow several plants to be planted back in a clump. This way you can get even more color with spectacular larger plantings of daylilies of your favorite or more expensive varieties or to give them to friends if you have too many.
Gently pull the plants apart while holding on to the base of the fans. While separating, make sure that the plants have a larger number of roots so the plant will cover rapidly.
Unlike the iris, daylily roots SHOULD NEVER BE CUT OFF.
If you cannot replant your daylilies immediately, keep them in a box in a shady, cooler spot layered with damp newspaper. Never let them dry out. Replant as soon as possible.
Older daylilies have a very short blooming period of only a few weeks. Newer varieties may even continue all summer season, so you might have to wait until later in August to dig and replant.
The bed in which you will plant the daylilies should be dug deeply so the soil is loose and roots can go deeply where soil is moist and cool. A digging fork works, as does a spade. Turn over the area and sprinkle a well-rounded fertilizer over the area along with gypsum if you have hard clay soil or caliche. A covering of about 3-4 inches of mulch is an excellent idea to hold moisture, keep the soil loose and porous, plus the mulch will feed roots organically. Turn this under again, breaking all the larger clods, mixing well then raking smooth.
Daylilies fare better in the soil than out, with leaves turning yellow within only a few days. When planting, dig the planting rather deep with your trowel to accommodate fat finger-like roots. Make certain they're not "stuffed" in the hole but have room to spread out and grow.
Take care not to plant too deeply or too shallow. Soil should end up slightly over where the roots emerge from the fans with only about an inch or so covering them. Firm, but don't pack the soil and water well. Covering the area with another inch of mulch will get them off to a good start by making any weed pulling easier and help cut down on your water bill.
Check the area every few days to see if the soil is dry and needs to be watered again. They like to be moist but not soggy. Good drainage is a must with daylilies and other perennials. You may want to use Superthrive in a watering can after you've watered to help root production, or a light dose of Miraclegro every few weeks.
Daylilies are one of the easiest and most rewarding of perennials that do well here. They increase well and are bothered by few pests. Their colors are bold to delicate and although their flowers only last a day, hence their name, they usually form so many bloom stalks and additional flowers that it's hard to know where one begins and one is past bloom.
Newer varieties or hybrids are not the old strappy "diploid" types with fewer chromosomes that resulted in spidery blossoms that did not have much of a bloom season. New "tetraploid" have more chromosomes, larger, wider petals with thicker flowers and considerably more substance and an extended bloom season, often reblooming in fall if well fed. Many have "eyes" of a darker color or even contrasting color that will dazzle you. Many are fringed or almost fluted with bright, new deep colors to rival our Arizona sunsets.
Smaller border daylilies have won our hearts with miniature clumps of bright flowers rising above very neat, compact plants. There are daylilies for everyone to enjoy in every part of the garden.
Every year I have questions about "re-blooming iris," especially why some gardeners have trouble with them.
Number one, not all re-blooming iris re-bloom in all areas of the country. Some are proven re-bloomers in some areas, but because of early cold many do not at our elevation. Also, iris have to be in the ground undisturbed for at least two years to re-bloom and many require even longer. Iris that have not been extremely well fed will not re-bloom in fall or even the following spring. Gentle, monthly feedings work better for perennials that store food in their roots. Add a few heavy feedings when planting, before bloom and in early fall (with Winterize) so roots can stockpile extra nutrition for following years. Winter watering every few weeks will keep all the perennials healthy, even when the ground is frozen, so they can survive those dehydrating winter winds.
(Kate King is a longtime Yavapai County resident and Master Gardener. Contact her at firstname.lastname@example.org)