"What Do I Do With All These Potted Mums?" Your fall gardening questions, answered
For this week's blog post, I turned to my friends to ask if they had any fall gardening questions. They did not disappoint! Here are several of their questions, along with my responses.
Q: Our garden has finished producing for the summer. When is the right time of year to remove the plants from the garden (raised bed)? Now or in the spring? Or does it really matter? We have green beans, limas, cucs, tomatoes, eggplant, peppers, zucchini & yellow squash vines.
A: You could remove plants now if they are no longer bearing fruit. For any plants still bearing fruit (e.g. tomatoes), you could wait until just before the cold sets in and after there's no more hope of Indian Summer -- for me, this is usually the first week of November. Regardless of when you remove dead plants, make sure you do compost them before winter sets in – otherwise, they might provide a place for pests to overwinter. Along with this, if any of your plants are diseased, get rid of them now. For example, this year ALL of my squash plants were infested with squash bugs. These "true bugs" (Hemiptera) sucked the life out of my zucchinis and pumpkins until they were ghostly white and withered. I pulled every bit of those dying plants out, along with the many bugs that were still suckling on them, bagged them, and sent them to the city. Depending on the disease or pest, you probably don't want to compost sick plants in your own yard, lest those diseases come back the following year.
I make an exception for perennials and annuals that have seeds for birds, or that have winter appeal (e.g. ornamental grasses). As long as they're not diseased, you can safely compost them in the spring.
Q: How do you prepare a bed for the best spring and summer soil?
A: Clear away all dead plant matter and add a thick layer of compost (three to six inches) to the top of your beds now, gently turning it into the top layer of soil. Then let it rest and continue to break down over the winter. This is perhaps the best option for preparing your gardens for the spring. If you don't have any available compost yet, you can wait until the early spring. At that time, the process is just about the same -- spread a thick layer of compost across the top of your garden, gently tilling it in (avoid overly disturbing your soil, as this can lead to soil compaction as soil settles from being tilled). You could also plant a "green manure" (AKA a "cover crop"), which is a type of crop you sow and let grow until the freeze, then till into the soil in the early spring. Depending on which types of seeds you plant (options include various legumes, sorghum, millet, buckwheat, and so on) the plants will fix nitrogen in the soil and/or provide organic matter when you till it in later on.
Q: Is it too late to move my hydrangea?
A: Hydrangeas are deciduous (woody) shrubs. While this forum says to transplant them in October, another source says to transplant them after their leaves have fallen and they've gone fully dormant, in November or so. I would imagine that the best times to transplant hydrangeas would be very late fall (when the ground is still soft) or very early spring. I transplanted three hydrangeas last spring and they survived, even through the drought – but I had to water them a lot. Whatever you do, just make sure you keep your hydrangea hydrated.
Q: I just bought a few hardy mums in plastic pots for fall decor. Can I keep them in the pots over the winter, perhaps on my porch or near the foundation of the house where it's warmer, and then plant them in the spring?
A: My understanding is that many mums are on the tender side and may not survive a harsher winter -- especially with their roots above ground. If you don't want to plant them now (you can do so up until the ground freezes), find a warm location on your property (for example on the south side, if there's sun exposure) and "heel in" the pots. Submerging the roots in their pots insulates them and gives them a better chance of making it through the winter. I take the potted perennials I didn't get around to planting and heel them in to one of my raised beds. This worked very well for the sedums, mums, and other perennial divisions I wanted to save over the winter of 2011-12. I successfully transplanted them all last spring. Here's a photo of this year's leftover perennials, which I just dug into one of my raised beds:
Q: I use vermicompost, but what application technique do you recommend? Can it be used to fertilize my mature pear tree? Also, should I reapply throughout the summer?
A: Vermicompost can be used to fertilize trees, shrubs, perennials, annuals and even grass, and a little goes a long way. You can fertilize any time of year without harm, though it's best to use vermicompost when your plants aren't dormant, in spring and summer. You can simply sprinkle some vermicompost around the base of a plant, OR (and this is my preferred method) you could make compost tea. Mix a scoop of vermicompost (1/2 to 1 cup) with a gallon of distilled water and use the solution to water around the plant. If you want to go a step further, you could use an aquatic air pump and a little molasses and make your own super-charged compost tea a la this method. This encourages increased growth of the beneficial microorganisms in the compost and makes for healthier, happier plants.
Q: I just had my first garden this year. What do I do now? Some tomatoes and strawberry plants are still alive.
A: You can leave your strawberry plants in place and mulch them in late fall for added winter insulation. Some people will mow them down after immediately they've borne fruit (this is called renovating), though you should not cut them in the fall, as you may remove blossom buds for next year's crop. As for your tomatoes, if they're still growing (the "indeterminate" varieties will grow on and on until it's too cold for them) leave them as long as you can -- again, I usually leave mine until Indian summer is over. At that time, I pick every single remaining fruit -- even the tiny, slightly withered green ones -- and put them a paper bag. This helps ripen the tomatoes. Then I will use them to make chili or creamy tomato soup.
Q: What about fall pruning?
A: Generally speaking, it's best to prune shrubs and trees when a plant is dormant. Right now most plants are in the process of going dormant, but are perhaps not there yet. Since pruning stimulates new growth and can attract pests, pruning them just before a freeze might endanger the tree or shrub. So it's best to wait until late winter to prune, when your plants are dormant. According to the UW-Extension Master Gardener Manual, "the best time to prune most deciduous trees and shrubs is during late winter, before plants begin to leaf out in spring. Pruning cuts heal most quickly in spring, and diseases and insects that spread diseases are dormant during winter."
Q: Bulbs! Which ones to plant now, which ones should come out into storage. Also: how do you best to transplant bulbs across zones?
A: The only bulbs I grow – mainly tulips, daffodils, and alliums – were planted by a previous owner of my home. I simply let them bloom in the spring, cut them down when they're finished and leave them for next year. That's the beauty of hardy bulbs – they're pretty low maintenance. Now if you're talking about tender bulbs – dahlias and canna lilies come to mind – you do have to over-winter them indoors. My mother-in-law does this with her beautiful and extensive dahlia collection. Here's a helpful article from the University of Minnesota Extension that breaks down the steps involved in storing tender bulbs, from gently digging them up to curing and storing them.
As for planting bulbs, I consulted with my UW-Extension materials and the best time to plant tender bulbs is in the spring, after the last frost; hardy bulbs should be planted in Wisconsin in mid-October, slightly later for the hardiest of bulbs (e.g. tulips). You can transplant bulbs any time they are dormant (when the leaves have died back). How deep should you plant them? "Hardy bulbs should be planted at a depth 2 1/2 times their circumference."
Q: What can you tell me about gardening year round?
A: It is possible to grow year-round, though depending on where you live this can be a costly and time-consuming endeavor. Here in the Milwaukee area, you need a heated greenhouse to grow in the winter. My own property is much too small for this. I have grown herbs, spinach and lettuce with some success under grow lights inside my home (see this post to learn how to make your own grow light area without spending a fortune). I also have several potted dwarf fruit trees -- pomegranate, fig, orange, banana, coffee. I put them outside in summer and bring them in around October 1. None of them have borne enough fruit to be worth mentioning, though the tiny, super-tart oranges I got a couple years ago were great in mixed drinks!
Growing indoors is hard because plants will never get the amount of light inside our homes that they really need. I remember in my Master Gardener training our teacher told us that even the sunniest window is darker than a densely shaded forest. This causes most indoor plants to go dormant, meaning they won't produce much at all. The other problem that comes with raising plants indoors is fungus gnats. These tiny creatures are the bane of any indoor gardener's existence and are very hard to control without chemicals. Having said all that, I still think it can be a fun and rewarding challenge to grow herbs, lettuce, and spinach indoors, and I always start my garden plants indoors in the winter and grow them under lights in my basement, as well as in a mini-greenhouse in my kitchen.
One of the best things to grow outdoors *almost* year round is spinach. It's very cold-hardy and I've found it growing well into the late fall and then again in very early spring. Give it a try!
Do you have a question about gardening? E-mail me at heatherzydek(at)gmail(dot)com and I'll try to find an answer for you!
Until then, I'll close with this photo of my favorite plant this fall:
How to Dry Herbs
I admit I'm much better at growing food than I am at preserving it. My small urban lot only produces so much in the way of tomatoes, zucchini, and carrots. Most years, I manage to cook everything I've grown for our family of five before it goes bad. So I have yet to figure out canning.
That said, I do preserve some of the herbs that grow on my tiny "farm." I grow a lot of them – everything from basil to tarragon and lovage – and while I don't save all my herbs when the cold winds blow in, I do like to preserve the things I may use in the winter.
