“Can I grow potatoes in a 4’X4′ raised bed or do I need something deeper like a garbage can with holes in it? Thanks!” Question from Patricia Froehner or Newton, New Jersey
Answer: Absolutely! Large, soil-filled cans and tubs are convenient for growing potatoes in small-space gardens, but they are not necessary at all. The key to growing really nice potatoes is providing rich, lightweight, porous soil with some depth. That is very easy to provide in a raised bed. If you already have soil in the bed, it is always good to amend it each year with a quality compost to lighten it and add fresh organic matter. Potatoes are also heavy feeders, so be sure to add a quality fertilizer formulated for vegetable growing.
There is one other thing that you need to know about growing potatoes. They are prone to a very destructive insect called the Colorado Potato Beetle. If you grow potatoes, these pests are almost certain to show up. If left unmanaged, they can absolutely destroy a potato crop in no time. Here is more about managing these pests.
Colorado Potato Beetle IPM
Colorado potato beetles mating on top of a potato plant.
The surest way to attract Colorado potato beetles to your garden is to plant potatoes. The fat, striped adult beetles emerge from the soil in late spring to feed on emerging potatoes and then lay clusters of orange-yellow eggs on the leaf undersides. The eggs yield highly destructive little orange larvae that eat foliage nonstop and grow very quickly. You can kill the insects at any stage, but it’s easiest to pick off the adults and eggs. (Click here to view the full life cycle of these beetles.) The beetles can complete up to three life cycles in a single season, so once you have them, you generally have to fight them all summer.
Colorado potato beetle larvae (left) on tomato.
These pests are highly resistant to insecticides, so it pays to choose non-chemical methods of control. Time and time again, well-timed cultural control, and good fall cleanup (removing old plant pieces and leaves) have proven to be the best means of battling them. Cultural control is essentially “picking”off the adults, eggs, and larvae and/or pruning off egg- and larval-covered leaves and stems. I generally smash the beetles as I pick them off, but you can also drown them in a bucket of water. Good picking should start in mid to late spring and continue until all signs of these pests are gone. (To learn everything there is to know about Colorado Potato Beetles, visit potatobeetle.org.)
I hope that these tips help!
Happy Gardening,
Jessie Keith
Black Gold Horticulturist
