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The Flower Show

June Gardening Tips: Your Monthly Checklist

June 13, 2024

leaf icon gardening

leaf icon planting

community garden tomatoes

By Sally McCabe, PHS Associate Director of Community Education 

June is a busy time in the garden when many are tending to their vegetable gardens in anticipation of summer harvests. Below are some timely tips to make sure your garden is on track this month! 

tomato cage

Cage Your Tomatoes 

Cage your tomatoes NOW, before they get too big. Heavy duty cages are best; but if you’re using the wimpy kind, attach three together with zip ties so they can support each other, and hammer a stake through one of them for extra stability. If you really want to remember the variety as it matures, attach the labels with duct tape or wire to the TOP of the cage rather than sticking them in the ground. Once your tomatoes start growing like crazy, you’ll be lucky to even find the ground! In this case, the cages are also handy to mark the plants, so you know where to water them. 

deadheading a flower

Remove Done Flowers  

Remove done flowers from annuals to keep them blooming. The plants’ entire purpose in life is to ripen flowers into seeds so they can call it quits. Thwarting that process forces them to push out another set of flowers, and another and another, until either frost kills them, or we skip a week deflowering them, in which case they win.  

repotting plant

Keep a Pot and Soil Handy 

Always keep a pot and soil handy by your front door, or wherever you know you’ll see it and reach for it. Countless times, I’ve walked around with a gifted or not-so-gifted plant in my hand, gotten home, and set it in a “safe” place. Three days later, it’s either totally limp or totally crisp (the only exception being a succulent rescued by my youngest and still perfectly fine after months in the car’s ash tray!). If only I’d had a pot of soil ready, said plant would be flourishing right now. A plastic bag in the pocket is also a must-have as a temporary safe place. Stocking these materials and keeping them in places you know you’ll reach for them will help you stay on top of garden and plant maintenance.  

spraying plants

Search and Spray for Aphids in the Garden 

Aphids are hanging out on the undersides of everything, but haven’t started partying yet, so a spray of insecticidal soap should keep them under control for a while. However, don’t spray if the aphids are looking pearly grey instead of translucent; these mummies show that they have been parasitized by tiny wasps and are being controlled from within. Leave these zombies alone to roam the garden and consume little aphid brains to their heart’s content. 

mums

Crewcut Your Chrysanthemums 

Mums are fall bloomers but need some special care NOW for the best results THEN. Once they get to be about 6-8 inches, cut them back by half; when they grow back, do it again. And again. Once July 4th rolls around, do it one more time and then quit. Each time you cut the plant back, new growth branches, and the branches branch, and so on, and then each branch sets buds when you finally let it do its own thing. This judicious pruning makes for shorter, stockier plants and many, many more flowers come Fall. 

basil

Start Using Your Herbs 

Basil is especially lush right now but trying to push out flowers and mature. That's what we don't want it to do, so start clipping the tops off the plants and using them to make pesto! This is one of the joys of the beginning of Summer, so start harvesting bits of all your herbs; if using herbs fresh, it's best to pick them early in the morning before they start to dry out. An excess of fresh herbs can be chopped and frozen in ice cube trays with water. For drying herbs, there is no better place than the dashboard of your car. I spread paper out and cover it with fresh herbs; by the time I'm done a day in the sun, everything is dry to a crisp. Not as fast as a microwave, but with less risk of them bursting into flame. 

standing water in a pot

Keep Ahead of the Mosquitoes 

Standing water can be a major source of mosquitos, and it seems to take about three days of water standing before you can see those larvae, wriggling in anticipation of crawling out of the primordial ooze and enjoying a blood meal. Be diligent about dumping any standing water-- no matter how small an amount-- and treating the rest with mosquito dunks or sprinkles. I generally keep mosquitos under control by introducing cheap goldfish into the mix in larger reservoirs bigger than 30 gallons, avoiding water that sits in direct sunlight (gets too hot,) and where rainwater drops directly onto it, as this can cause the goldfish to get splashed out. I also avoid areas where it’s easy for cats to get to them. Marauding heron are rarely a problem in the city, but have been seen stealing the larger koi, so stick with the cheap fish. 

fertilizing plants

Side Dress with Compost and Fertilizer 

Vegetables are bursting out of the ground, seeming to double in size overnight; annuals are exploding with color after the recent rains. They’re getting all that energy from somewhere, and it’s not in unlimited supply. June is the time to charge their batteries with added fertilizer, and especially with some well-seasoned compost, spread an inch thick around plants on the surface of the soil. Fertilizer should be scratched lightly into the ground along the dripline of a plant, not too close to the stem where it can burn. Unless you see signs of color change in leaves of shrubs and trees, these rarely need to be fertilized, however, they always benefit from a top dressing of compost. 

plant seed packets

Do the Garden Math 

By late June it’s about four months until our average first frost date. I know it is hard to imagine ever being cold again…but if you are thinking of planting more warm-season stuff in the vegetable garden, use this as your timeline. That’s about 120 days. Read seed packets for days to maturity. This means no excuses—you can still plant about any summer crop except sweet potatoes, which generally take all those 120 days. 

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