By Sally McCabe, PHS Associate Director of Community Education 

September is a transitional time in the garden – as we enter into fall, it's a great time to take care of some garden clean-up, plant cover crops and perennials, plan for spring, and celebrate the season of harvest and fall transformation.  

Below is an overview of some key things to tackle in the garden during September to ensure a fruitful garden through the fall and plan a vibrant garden in the spring. 

Clean Up the Vegetable Garden 

Now that we can stand being outside again, it’s time to do some garden cleanup! Sadly, if you neglected the cleanup during the hottest months of the summer, more is liable to go out in trash bags rather than into the compost bin. Any weeds that have gone to seed need to be disposed of where they can do no harm - on a small property, that means into a trash truck. The same is true for anything showing disease. It is also important to clean up under tomatoes and especially under the grapevine; as fungal diseases splash up onto plants from last year’s debris, so get that stuff out of there! 

Plant a Cover Crop

This month, every time you pull out anything in the vegetable garden, add organic matter, turn the soil, and plant a cover crop. Fall cover crops control erosion, break up heavy soils, improve soil fertility, and reduce weeds. They sprout quickly, grow fast, and die young, often before they get a chance to bloom. Leave them on the soil surface, then dig them in during the spring to add organic matter. Legumes such as crimson clover, winter peas, hairy vetch, and subterranean clover also add nitrogen to the soil (prizes given for best definition for the last two!). Non-legumes include oats, wheat, barley, winter wheat, and rye. I don’t recommend radish or rapeseed in the city because they can harbor Harlequin bugs through the winter. 

Plant Perennials  

The markets are flooded with mums and asters right now, and they are BEAUTIFUL - just what we need to fill in where the heat killed off all the annuals! Plant them or leave them in pots and move them around, fooling your friends into thinking you have more than you do. However, mums generally don’t contribute much environmental function, so we also advocate for planting hellebores, catmint, Stachys, and hostas in the early fall as well.   

Shop for Bulbs 

Tulips, daffodils, and a host of minor bulbs are now available, even in the big box stores. The caveat is that you get what you pay for, and the size of the bulbs does matter. If you want a display that will last for years, bigger is always better. Additionally, PHS advocates for shopping local nurseries and garden centers when possible so keep an eye on your local spot’s inventory as well. 

Find a Festival!  

Unless you’ve been irrigating, heat and drought have brought the garden to an almost complete standstill. So, let’s enjoy the fruits of somebody else’s labors! Harvest fairs are popping up weekly now, and ads for u-pick apples are starting to creep in as well, so keep an eye on your local news outlets for festivals in your area or check out PickYourOwn.org to find a list of pick-your-own farms near you. Personally, I’ve done my fair share of knocking on people’s doors for permission to pick apples when I see a heavily laden branch hanging over a gate or the sidewalk. 

Keep Picking Veggies! 

Keep picking those tomatoes, peppers, and eggplants! If they’ve survived this long, they’ll continue to bear fruit if you keep picking the ripe stuff. In fact, since there are only 6 weeks left in the tomato season, harvest tomatoes a little early; this will hustle the next crop of green ones along to ripen before the summer’s over. 

September is also a great time to do some “Last Chance” gardening. This is almost the last occasion for planting lettuce, mustard, and basic greens if you want them big enough to feast on by Thanksgiving, or even to survive the winter.  It may be hard to think about that when the temps are still in the eighties, but it's true! 

With all of these things in mind, you’ll be prepared for the transitional time in the garden that is September and keep your garden both beautiful and functional through the fall.