September means gardens are now heading into the season finale with harvests of tomatoes, beans, squash, cukes, onions, potatoes, and peppers leading the way!  Wet weather has been hard on some veggies and flowers this summer but there are some special techniques to keep plants healthy despite the saturated soils.  This is a good time of year to apply foliar compost tea and your own homemade biofertilizers. It’s also a good time to get a soil test so you know what is needed for next year.  Tomatoes, peppers, broccoli, and cabbage will do well if you follow a few basic tips to extend the season and keep them healthy.  Late summer pests & diseases are appearing too so let’s be alert.

Got wet soils?  The recent rains have filled the soil with water and squeezed out vital oxygen that beneficial soil bacteria require to break down organic matter into plant nutrients. The result is that water soluble nutrients like Nitrogen and Potassium can be washed away and other nutrients are not available to plants. The resulting poor growth can be corrected with additional foliar fertilization to replace the missing nutrients.  This is especially important for perennials that need to store nutrients for next year but also for our annual vegetables and flowers that need food right now.  I have been giving extra granular organic fertilizer directly to garden plants (tomatoes, peppers, squashes, broccoli, cauliflower, etc.) as well as side dressings of compost. Applied just before rain this replaces the lost nutrients needed for growth and disease resistance.  A quicker remedy is to apply foliar fertilizer so the leaves can absorb nutrients that the waterlogged roots are unable to get.  More details below.

Soil Testing is a simple and important task we all should do this time of year.  Fertilizing your soil without a soil test is like taking medications without knowing what, if anything, is wrong.  Bad idea and possibly a waste.  The University of Vermont Extension service provides a good soil analysis and recommendations report.  Get their simple directions online here, mail in your soil sample in a clean plastic bag with $17 and they will send you the information by email or regular post to make your garden or lawn better.

What to Plant in September?  Seeds or transplants of lettuces, arugula, spinach, kale, & radishes will do well.  Keep planting those empty spaces!

Late Season Tomato care.  August & September conditions generally are good for a plant’s growth, but some plant diseases appear now.  Plant diseases can’t be cured, only prevented and managed.  Most important is disease resistant varietal selection, but that’s a discussion for January when we select our seeds.

Disease prevention is the most effective strategy.  Healthy plants can resist pests and diseases and healthy soil is the best way to have strong, healthy plants.  Of course, healthy plants are more nutritious to eat, so they contribute to our own good health too.  Homemade compost supplemented with minerals like phosphate, calcium, and potassium, when indicated by a soil test (see below), are a great way to build healthy soil and reduce disease problems.  

If your garden plants seem to be losing their vigor (slow growth, yellowed leaves, etc.), it’s time to give them a nutritional boost.  Foliar (leaf) feeding is quickly ingested and can extend the production of tired tomatoes, summer & winter squash, cucumbers, peppers, and many flowers that have used or lost the nutrients from waterlogged soil.  Fish emulsion (available at most garden centers and online as a liquid concentrate) is a great fertilizer, best applied in the morning (when leaf pores, stomata, are open and can take in the food) and when no rain is expected.  Spray it on with a tank sprayer or with a watering can with a sprinkler head. I’m also experimenting with fermented plant extracts and biofertilizers as foliar supplements to provide a balanced nutrient food for plants.

You can also apply a commercial liquid organic fertilizer when watering.  Got compost?  Make a simple “compost tea” with a shovel-full of mature compost in a 5-gallon bucket and fill with water.  Mix it well and repeat mixing a couple times for a day before watering your plants with this healthy probiotic tea.  This provides a great boost of beneficial soil microbes plus some nutrients to feed your plants.  Do not try to save it for more than a day or two, it can get pretty “ripe”!

It’s also important to regularly remove all diseased or yellowing leaves/branches from plants.  An infected leaf can produce millions of spores that quickly spread over the surface of healthy leaves as well as inside the plant via sap.  Cut them off and discard away from the garden, not in your compost.  Continue to pinch off “suckers” and harvest ripe tomatoes, peppers, cukes, etc. so the plant’s strength can go to new fruits. 

Finally, tomatoes and peppers are really sub-tropical plants and don’t know that winter is coming so they are still trying to grow.  Because it takes 50-60 days for a tomato blossom to grow into a ripening fruit, blossoms forming after Sept. 1 will not yield usable tomatoes but will take valuable energy away from the plant.  Best practice is to snip off all newly formed blossoms after Sept. 1.  Sad thing to do but it will direct more energy into the fruits already on the plant.  Also, if your plants have outgrown their supports then cut off the terminal tips to stop excessive growth at the top.

Perennials.  September is a good time to dig up and divide oversized perennials (hostas, lilies, etc.).  They will have enough time to re-establish some root growth to withstand winter.  Dig them out and cut them with your spade or garden knife into moveable clumps for transplanting.  Be sure to put a couple tablespoons of rock phosphate (or bone meal) into the planting hole before placing the plant.  This will provide a source of this root stimulating nutrient for years to come. Top the soil with compost to feed them into winter and next spring.

Thinking ahead… now is the time to order your fall bulbs for October-November planting.  If you haven’t grown garlic, this can be the year you start.  Order “seed garlic” from a local farmer, Johnny’s Selected Seeds, FEDCO, Maine Potato Lady, or other online sources for late October planting.  Supermarket garlic is probably the wrong variety and may be treated to inhibit growth so doesn’t make good seed.

Pest Alerts. 

Snails & slugs love these wet conditions and continue to damage plants and are laying most of their eggs for next year.  Control them with coffee grounds, beer traps, slug baits (Sluggo, etc.), diatomaceous earth (DE), and hand picking.  Hand picking also is effective.

Cabbage loopers on broccoli, cauliflower, cabbage, kale, etc. will be very active in the cooler, fall weather.  This white or yellowish moth can be controlled with Bt (Dipel) and a butterfly net (if you’re quick).

Get the Weeds!  It’s easy to let the weeds finally have their way in the garden.  Do not stop now!  Weeds are now producing their seeds for next year, and several years after that.  Weeding now will yield benefits of reduced work in the future if you remove those plants, or at least the seed heads on top.  It’s an important goal, do not allow weeds to go to seed in your garden!  Use the seed-free weeds as compost or mulch.

Make more Compost!  This time of year we have an abundance of ingredients for the compost bins.  Garden plants, grass clippings, fruit & veggie scraps, and autumn leaves (soon) all produce the best soil amendments.  Here is a comprehensive website to all things compost.