Down the Garden Path

Richard Hentschel, Extension Educator

Clearly our blooming plants are ahead of schedule since we had such a warm March. Horticulturists rely on a system called Growing Degree Days (GDD) for plant development, for monitoring for insects and disease. The GDD system uses a base temperature of 50 degrees to begin to calculate how many GDD we have had. Last week Northern Illinois was just a week ahead of schedule while Central and Southern Illinois remains two to three weeks ahead.

All that is well and good, but our plants are not following the GDD schedule very well this year. Gardeners are seeing plants with flower buds on them that should not being there for many weeks yet. I have seen and had reports from homeowners and Master Gardeners, all talking about how early our blooming plants are flowering. Arboretums had to cancel some of their spring bulb bloom shows because the bulbs came out and bloomed weeks ahead of their normally scheduled and publicized show dates. More locally, peonies which bloom around Memorial Day have for many varieties bloomed out, with just a few blooms remaining.

Surprisingly, some of our other late summer or fall blooming plants have already begun to set flower buds. Normally gardeners would be out pinching back fall mums to create shorter, bushier plants, yet some mums have already set flower buds. The big question is can you prune anyway and hope the mums set more buds for fall? The general opinion is that you should be able to prune now and still see mums set flowers for later this fall. You can experiment and maybe prune one of your mums back that is in a more out of the way place and see what happens. Mums should be setting buds based on a change of day length later in the summer.

Stonecrop sedum can also be found with flower buds forming well ahead of normal. Stonecrop sedums are normally a late summer fall bloomer. I believe what has been happening is that both mums and stonecrop sedum set buds as a response to our temperatures rather than day length. Gardeners are also seeing that those spring bulbs that did bloom so early have vegetatively grown bigger since they have had many days since blooming to put on lots of foliage. Hopefully that will translate into more or bigger bulbs and blooms in 2013. If our weather continues to moderate and we have cooler days and nights, our GDD day accumulation will continue to slow and get us closer to normal, although gardeners should expect to see more surprises in the garden and landscape as the season moves ahead.

Down the Garden Path

Richard Hentschel, Extension Educator

With our spring weather, every spring bulb has long ago finished blooming and now only the foliage tops remain. Our early and long spring has left lots of time for the bulb foliage to grow and actually be taller than it normally would be. For some gardeners this poses no problems at all depending on where in the beds the bulbs are, for others that foliage is now about to be in the way when getting ready to plant summer annuals. If your bulbs were back from the bed edge, you likely have room to go ahead and plant your summer bedding plants without interference and can let the bulb foliage die down naturally.

It is important to understand why gardeners leave the foliage as long as possible. Those leaves produce the energy that is so important to replenish the bulb for flowering in 2013. That same energy is also used to create new bulblets off of the mature bulbs that will in a couple of years be flowering as well. This is how nature has intended bulbs to multiple. Leaving the foliage as long as possible ensures that bulbs will have the ability to provide us with many years of flowers and the bulbs increase in numbers. As a gardener who is trying to increase the number of spring bulbs, fertilizing now and watering if it gets hot and dry again will be very helpful before the foliage naturally turns yellow and browns and eventually collapsing.

A tip that is helpful is if your bulb flowers were pollenated and are now producing a seed pod is to remove the seed heads, directing that energy back into the bulb.

In the past gardeners have bent the foliage over and used garden string or a rubber band to contain the bulb foliage. Another practice has been to "braid" the leaves together for the same purpose. In both cases, those inner leaves are not able to receive any sunlight, resulting in no food production that can benefit the bulb. These practices are not recommended any longer.

This time of year the bulb foliage has begun to weep over and take up a lot of space. If you need to clear away foliage, scoop up the foliage from a bulb in one hand and use the pruners in the other to just cut enough foliage so it stands up again. This method works well with daffodils. Most likely you can plant around the tulip foliage without much of a problem since tulip foliage is minimal compared to that of daffodils. By leaving as much of the bulb foliage as possible, you provide a bit of a backdrop for your newly planted bedding plants and the bed will not look quite so empty or new looking.

Although not directly related to your spring bulbs yet bulb related is that the soil has warmed so it is time to plan on getting your summer bulbs set out. Summer bulbs are pretty generic these days to include true bulbs and also corms, tumors, and roots (Gladiolas, Calla Lily, Cannas, and the tropicals like Elephant Ears are a few examples.)

Down the Garden Path

Richard Hentschel, Extension Educator

Retail Nurseries and Garden Centers carry a great many kinds of trees for our home landscape. There are understory trees for established landscapes that already have large growing shade trees. You can find ornamental trees that provide great fall color, a flower and later a fruit or seed pod of interest and are typically of a smaller size than the shade tree. Once your selection has been made and you have that tree at home, it is important to understand the differences of planting a container grown potted tree and one that has been field grown and now available as a balled and burlapped tree (B&B). In a lot of cases the smaller caliper trees can be found as container grown, while the larger sized trees will be the B&B.

In either case, the trees have been professionally grown with the kind of management that will ensure good survival and establishment in your home landscape. Container grown trees have their entire root system in the pot and need special attention when being planted. B&B trees differ in that a portion of their root system is left behind when dug, yet nursery grown trees have been root pruned earlier in their growing cycle to ensure more roots are closer to the trunk before they are dug.

When you are digging your hole for your newly purchased tree, that planting hole should be no deeper that the soil in the pot or the depth of the ball. The tree will benefit if the hole is wider that at the top than the bottom as this will allow newly expanding roots to more easily grow out into the that transitional backfilled soil. Planting at the correct depth is very important. If you feel the need for improving the soil drainage for the new tree, you can always plant the tree slightly shallower in the hole and allow the roots to seek their preferred level as the tree goes through the transplant recovery phase.

A critical difference in planting your potted tree vs. the B&B tree is the need to be sure any roots are not left to continue to circle as they likely have been, having been growing the container. You will need to work the soil away from the roots and gently or not so gently move those roots out in a radical pattern as they naturally would have grown. If you come across a root that is too woody to bend out, you are better off to prune it away so that the roots that form latter at the cut end begin to grow out naturally.

When you are planting a B&B tree, the critical part is being sure to remove the burlap and twine from around the trunk and over the shoulder of the ball. If your tree has a wire basket, cutting or bending down the wire over the shoulder should be done too.

The longer term attention you should l give your newly planted tree is watering. Watering is something we typically think about that first year, but not much longer. A good rule of thumb is that for every inch of trunk caliper, there is a year of recovery. So that second or third year, watering is still critical to the transplant recovery.