PROBLEMS THAT ARISE with container gardens generally have different solutions than those employed by large-scale, in-ground gardeners with their beds and rows and endless space (those smug bastards). As your new container garden begins to take hold, problems inevitably arise. But you have chosen to invest yourself in the adventure of container gardening, not the easy delights of planting a rolling meadow. The challenges are greater, but the rewards infinitely more satisfying! Still, there is one problem that comes up so often that it's worth taking on all by itself:
Even a month or more after transplant, my plants still look so small. How can I encourage them to grow larger and bushier, and produce more flowers/vegetables?Perhaps the greatest challenge of container gardening is to encourage the hearty growth and development of plants which are growing in non-ideal conditions. But that doesn't mean you need to throw in the towel or give up on lush vegetation. More than likely, you're coming up against one of these problems:
Container SizeProblem: You have planted those tiny seedlings in pots or baskets that truly are too small to contain the type of root system that this particular plant needs. Frequently, squeezed plants will start to die from the tips of their leaves inward.
Solution 1: Replant the specimen in a larger container or replace it with a plant that has a smaller or more condensed root system.
Solution 2: The bigger the plant, the larger root system it needs. If you're putting a already-large ("well-established") tomato plant, for example, in a smaller basket, don't hesitate to lop off longer or low-hanging branches when you pot it in the first place. You may be able to salvage an already-potted plant by ruthless pruning. A good rule of thumb is to take off about a third of the plant when pruning, and to take off longer, scraggly, or dusty/wilted branches first.
Chances are, of course, you have no idea what kind of root system this plant has or what plant would be better for this container. A large part of your potting experience will consist of pulling up plants, I'm sorry to say, but though it's a heartbreaking process you can learn a great deal from uprooting a dead specimen. Try to put your emotions aside as you pull out the failed plant, roots and all. Look at the root ball: is it spread out and shallow? Does it consist of one large, thick taproot surrounded by a few wispy roots? Are the roots bunched together or spread? Do they lie near the surface or burrow deeply? Remind yourself several times of the name of the plant, and try to impress upon your memory what the roots look like: "Okay, self, this is what Rosemary roots look like. They're deep and bunched together, so I probably shouldn't have planted it in that super-cute wide and shallow container."
I find it very difficult to throw away plants that are even marginally alive, and I always want to know what I did to nearly kill them. If I suspect a plant of being very much constricted by its pot, I sneak out in the dead of night and secretly plant the remains in the flowerbed of my apartment complex. It gets the same amount of sun, shade, and water as my porch; the only difference is the amount of space the root system now has. If the plant dies anyway, I assume that space was not the deciding factor and store that in my memory for that type of plant. If, however, it rockets to previously unimaginable heights and lushness, as two minute, near-death zucchini and squash plants did, I accept that container size was probably the issue. The illicit squashes, by the way, grew to a height of three feet in two weeks and were completely covered in blooms when they were discovered by the landscaping crew who- not realizing their tasty potential- uprooted them as weeds and tossed them aside to croak in the sun.
LightProblem: The average container garden is created in a less-than-ideal space. This frequently means that the area you have chosen- or more likely, had thrust upon you- only gets two to four hours of direct sunlight a day. You can ignore this or hope for the best and plant whatever you want anyway, but limited light will always come back to haunt you. Those suggestions for full sun on the back of seed packets are there for a reason: four hours of almost-direct sunlight does not equal eight hours of full sun, no matter how much you may wish it would.
Solution 1: Get used to stunted plants. You can grow full-sun plants in part shade, if you so desire, but they will not be bushy or thrifty. If you love a certain type of pansy, go ahead and try it. The worst that will happen is that it won't flower as well as it might. Or it may croak. But you'll be glad you tried.
Solution 2: Maximize your light. Look around your space at different times of the day to see if there is any one location that gets more light than the rest of the area. Install very light or reflective material in the darkest corners of your space (that ugly mirrored mosaic your aunt brought you back from Cabo will find new life and use in the high, dark corner of your porch). Replace your usual mulch around the base of the plants with white rocks to reflect light right back at the plants. If you can, repaint the interior of a dark porch in a light color. Repaint or scrub down already painted walls to reflect the maximum amount of sunlight. Cover a dark wood or painted concrete floor with a light-colored outdoor rug. Heck, make your own ugly mirrored mosaic, perfectly sized, to hang in a dark area.
Solution 3: Yield to the inevitable. If you get at most four hours of direct sunlight a day, the world of shade plants is open to you. Ferns, mosses, hostas, and plants found in densely shaded woodlands in your area are your best bet. Here in Memphis, the default state of the landscape is wooded hillsides, and a huge number of shade plants are native to the area. Check out what grows in your own forested areas to find surefire shade plants that will give you the bushy, lush look you want. And don't think of this as the cop-out version of your container garden: when you really get into them, ferns provide endless variations on the color green, as well as myriad textures and shapes. There are multiple varieties of flowering hostas, too, should you find yourself unable to part with the idea of a flowering garden.
Again, feel free to take what remains of a dying plant and quietly plant it in a nearby area with full sun. If the new location does the trick, you have your answer: your container area isn't bright enough to grow this.
SoilProblem: You bought the big bag of fancy soil at Stringer's (or your own local garden center), added some Osmacote, and planted your seedlings. Now, though, the leaves are yellow or brown, or they're falling off. The plant seems to be all stem and no leaves, or else it's so short it still looks like a seedling after two months.
Solution 1: You used too much fertilizer. Some plants, like Rosemary, do better with very poor soil; that is, soil with almost no nutrients at all. Generally, plants that like poor soil come from very dry areas (think non-irrigated California weather, or the South of France), but you can look up your plant and find out whether it likes rich or poor soil. If the plant likes rich soil, though, more is not always better. Too much fertilizer can cause chemical burns on your plants. Yellow leaves that drop off can indicate fertilizer overload (or that you're watering too often). Leggy plants- that is, plants that have long, scraggly stems and relatively few leaves- are another indication of over-fertilization. Take out the seedlings, toss out the potting soil in your container, and fill it back up with potting soil without adding any Osmacote or additional fertilizer. You can always fertilize the plants later by adding water-soluble fertilizer to a gallon of water.
Solution 2: You didn't use enough fertilizer. Plants look stunted and short even several weeks after transplanting. Be warned, though, that this is more likely a result of not enough sun; with the rich potting soil mixes used today, you're far more likely to end up with an over-fertilized plant than an under-fertilized one. Unless you dug up a wheelbarrow of dirt from a construction site, you probably are not underfertilizing.
At all times, remember: if a plant isn't working, replace it. Try something new and different in that space, or move your containers around within the space you already have. One of the great bonuses of the container garden is the ease and speed at which you can change out one type of plant for another. Don't let your entire spring and summer go by while you stare at spindly, unthrifty plants which clearly aren't working in your space. Embrace your opportunity to change out plants quickly and easily.
