Sunday, September 30, 2012


     That is my answer to clients who have been calling to ask about putting mulch down for the winter. It is still good planting weather out there. We can't even plant bulbs for another month because it is too warm -- and it is supposed to hit 80 one day next week. So let us not be in too big a hurry to welcome winter back.

     Many people put down mulch way too early because they don't really understand what it does. It's job is not to keep plants warm like a sweater. Rather its main job is to keep the temperature around plant roots from fluctuating wildly.

     Most of us in Chicago are aware of the lake's effect on temperature. Since the denser water changes temperature more slowly than the air, the shore area tends to stay cooler during the day and warmer at night. Similarly, lake shore temperatures tend to be cooler during spring and summer and warmer during fall and winter.

     The land acts the same way. It changes temperature more slowly than the air above it, and the deeper down you go the less affected it is by air temperature.

     By adding an extra layer on top, your mulch is in effect pushing your plant roots further down and making them less subject, not so much to cold weather per se, but to the variations in temperature that those of us above ground love so much.  Those variations may include a -30 degree cold snap that lasts a day or two. But they also include those January thaw days, and the cycles of freezing and thawing that cause frost heave in our plants and even kill them.

     Plants respond to the shorter days and lower temperatures of fall by beginning to shut more and more processes down and going dormant. When we put down mulch too early, we are fooling our plants into staying active longer than they should. So lets not get into too big a rush. Let your plants go through several hard freezes when your thermometer breaks 20 degrees before you reach for the mulching shovel.

Sunday, September 16, 2012


     It is mid-September and no longer summer mainly in the sense that our weeks in the 90's are probably over and we can stray from our AC units. The average first frost date here is supposed to be October 15, but I am betting we get at least two weeks to a month longer. My fall crop of snow peas planted the second half of August are doing well, and the spinach seeds that I procrastinated planting popped up last week. Along with my parsley, broccoli and Brussels sprouts, they should continue to thrive through the first several frosts.

     September is one of the best months to plant trees, shrubs and perennials. The soil is still warm. The early, energy-consuming spurts of growth are over, and the roots can comfortably establish themselves before winter. You can plant perennials as long as there is enough foliage left to determine that the plant is healthy. If I cannot tell, I prefer to wait. Trees and shrubs can be planted as long as you can get a shovel in the ground.  We have plenty of time left to figure out what to do with them, although you should keep in mind that nurseries want to run out of stock before winter, so your selection will become more and more limited.

     The same thing is true of bulbs. Moreover, the best way to buy bulbs is mail-order, so you need a little lead time for that. Most nurseries will keep your babies safe in a controlled environment until they think it is time for you to plant in late October or November, but you will have them reserved and don't have to fear  that they will no longer be available. We can talk more about planting when the time comes closer. For now you need to begin deciding what you want. For more about bulbs you can see my entries last November.

     If you want to throw your money away on tulips that last only a few years, be my guest. But be sure to include in addition some  perennial workhorses that naturalize in your garden and provide those wonderful harbingers of spring year after year. I am talking about spring bulbs like Crocus, Muscari (grape hyacinths). Narcissi (daffodils), and Galanthus (snowdrops).

     The smaller and earlier-blooming Crocus and Snowdrops can be planted directly in the lawn if you wish. Their bloom will be over before the grass begins to grow and they can be mowed right along with the rest. I like to tuck my larger bulbs behind perennials. There they can shine while your other plants are barely noticeable, but as they fade the later plants grow up to conceal them.

     But above all, think big. Don't plant some spindly little row  of 20 bulbs that will barely be noticed. Follow the instructions for your plant and pack as many bulbs in each square foot as you can. If you want to experiment first or have a small budget, pack all the bulbs you can into one square foot and then add more next fall. I know neighbors with small to medium yards who have 6000 bulbs planted and the yard is not crowded. Just make sure you can still see your perennials when you plant so you can plant all around them.

   Bulbs are one of the most under-utilized elements in the garden palette. Planted with enthusiasm they can be spectacular -- and add weeks to our spring flowering season. So go wild!

Tuesday, September 4, 2012

Sweet Autumn Clematis

Clematis paniculata

     Sweet Autumn  Clematis is a controversial plant. Botanists cannot even agree on what its Latin name is. Besides C. paniculata, other candidates for the plant include C. terniflora and C. maximowicziana (seriously!).

     This vine has many champions for many good reasons. It is a robust grower; it seems to thrive on neglect (for us lazy gardeners); and it even blooms in the shade. Best of all, you can train it to climb over any ugly spot you have in the yard. And it has a lovely perfume in bloom. There are few plants in the garden as spectacularly beautiful in September.

     Alas, our Sweet Autumn has her detractors as well. For one thing, she arrived here from Japan in 1864. That is well before many of us arrived here, but it still does not make her a native. Most of us plant people have nothing against "foreign" plants -- as long as they don't escape the garden and begin competing with our native species in the wild. Sweet Autumn is not on Chicago Botanic Garden's invasive list. It is, however, a "robust" grower. One expert describes it as "extremely vigorous to the point of

     I have worked with one of these vines for 10 years or more, and I had to dig it up and relocate it about 5 years ago. It was easy to transplant and, after a tenuous first year, re-established itself in new territory. In all that time I found it both pretty and well behaved. This year, however, it really took off and began scrambling all over the ruin of an old wooden play set. This is exactly what my client wanted to happen. Vigorous growth does not seem to be a problem so long as you know that you have to train the plant, prune ruthlessly in late winter and then chop away over the season. Planting in partial shade will also slow it down and give us lazy people time to react when it grows where we don't want it.

     The other new development this year, however, was the appearance of new seedlings in various parts of the yard -- including some that were trying to climb up the AC units. So much for the lazy gardener. This year, at least, I will have to be on the alert to remove these uninvited guests before they get established. Still, one year of aggravation out of ten is not so bad, and my client's "ruin" looks gorgeous.

     But don't say that I didn't warn you.