A cluster of tomatoes illustrates the ugly progression of late blight through my small kitchen garden. I’m losing about a bushel of tomatoes to the horrible disease.
It’s not news to anyone who owns a small kitchen garden: This has been a challenging year for gardeners in North America. I’m sorry if this was your first year planting a kitchen garden; I hope the aggravation wasn’t enough to discourage you in coming years.
The south western United States experienced sustained heat and dryness; I heard complaints from gardeners that they couldn’t keep plants watered and cool enough to get decent harvests.
The Atlantic coast and clear out to the Midwest had crazy, sustained rains and cool temperatures. Especially in the north—from New York up into Canada, rain drowned the roots of vegetable plants, and the cool temperatures slowed growth.
Late Blight and Tomatoes
Perhaps worst of all this growing season: Late blight, the fungus that created the Irish potato famine in 1845, shipped along with tomato seedlings to big-box garden centers all over the eastern United States. Late blight thrives in the cool-wet, and for the most part, tomatoes didn’t have a chance.
I completely fell in love with these tomatoes in 2009. Shaped like peppers, they grow quite large. They are so devoid of moisture that they float in water where beefsteaks and other slicing tomatoes sink. They taste terrific. Sadly, the last twenty or so still in my garden are infected with late blight.
According to the Encyclopedia Britannica, late blight is an American export; someone accidentally introduced it to Ireland. I long ago learned that the late blight fungus is pretty much always on-hand, waiting for the right conditions to kick it into action. A gardener’s best defense against late blight is culture:
- Provide good drainage— If drainage is good, air movement around your plants’ roots is also good; and good for the plants..
- Minimize moisture— Water only as much as the plants need; I haven’t met a vegetable plant that wants its roots wet constantly.
- Control moisture— That is, focus watering on the soil near plants’ roots; don’t use sprinklers and spray nozzles that soak foliage with every watering.
- Don’t crowd plants— You can plant things closer than seed packages recommend and you’ll get great production… as long as everything else goes right. I understand the risks of crowding and I take the lumps when they come… but please choose a level of pain that’s acceptable to you. Crowding traps moisture, blocks air flow, and provides easy pathways for insects and diseases.
- Make sure air can circulate freely— If there’s a lot of air movement within your garden plot, plants will tolerate crowding better than they will in a well-sheltered area.
- Rotate crops— Don’t plant the same crop in the same area two years in a row. Ideally, figure a three- or four-year rotation; don’t repeat tomatoes in the same space for three or four years if you can avoid it.
- Follow a crop only with crops that aren’t closely-related— Tomatoes, potatoes, peppers, and eggplant are all related closely enough that if you plant one in a specific area this season, none should go in that area next season. Please check my small kitchen garden store for books that will guide you to responsible choices for next year’s crops.
- Prevent the spread of disease— Remove sick plants quickly. Bag them and toss them in the garbage, but don’t compost them.
- Plant seedlings grown locally— Best of all: learn to start your own plants from seeds about four-to-six weeks before you put them in your garden. If you prefer to leave that hassle to someone else, at least find a local nursery or garden store that starts its own seedlings. The farther you go for your live plants, the more opportunities the plants have to acquire unwanted pathogens.
I feel pretty confident in guessing that this bell pepper is inflicted with late blight. I had been anticipating a second wave of peppers to harvest in early autumn, but the very difficult growing season had other ideas.
I got very lucky this season:
- I started all my plants from seeds for the first time ever.
- The micro climate of central PA was cool but “wet enough” meaning we got rain when we needed it, but not to excess. I’m quite sure it was low temperatures that caused the most trouble.
- Despite heavy crowding, my plants showed no sign of stress until late August.
- By late August, I’d already harvested about 3 bushels of tomatoes
- Late blight spread very slowly in my garden; it seems to have missed the potatoes, though it seems to be damaging some of my peppers.
Despite the good luck, in just two weeks, my tomato plants have gone from late-season production of gorgeous fruits to overwhelming melt-down with nearly every fruit showing ugly brown lesions. I’m used to harvesting tomatoes up to the first frost, but this weekend I’ll be pulling all the plants and stuffing them into a plastic bag for garbage pickup.
Keep On Gardening
This was an unusual year! It is my first in fourteen seasons at this address where disease has taken hold… and some of those years were far wetter. My guess is that the temperature was the biggest villain in my garden’s problems; summer seemed to last about two weeks. Those weeks fell between three months of early spring and the sudden onset of autumn.
So, don’t be discouraged. Chances are, next season will be “normal…” and if not, perhaps the season after that will be.