July 2019
By Scott Canning, Director of Horticulture and Special Projects

Ah, July! After living on the East Coast for many years, where July can be quite unbearably humid, I truly rejoice at our “monsoon season”. Just when it threatens to get hot, we can be blessed by an afternoon thunderstorm, and all is right with the world!

In July, the fever-pitch of spring gardening begins to slow down. Your planting should be pretty much wrapped up, but you can almost always plant larger containers and “B&B”, or “balled and burlapped”, nursery stock-it just requires extra vigilance this time of year. You can still plant seed, such as successional rows of vegetable crops, and summer is the time to plant seed of many perennials, like hollyhocks. They will germinate pretty quickly, and have time to develop into a rosette of leaves or a small plant that will survive winter. And some annuals are still available to fill holes in the garden, like the hole left by the exceedingly ungraceful exit of an oriental poppy planted too close to the front of a bed. Plan to move that poppy back when it reappears in September…

Try to finish fertilizing of woody plants by mid-month; you don’t want to add a lot of nutrients, especially nitrogen, late in the summer because it will tend to force new, soft growth that may not “harden” before frosty temperatures arrive. Feel free to continue incorporating aged compost; it feeds the soil and tends not to “push” plants. Remember to moisten your compost pile, and maybe add some manure or extra green waste, both sources of nitrogen, to keep it “cooking”.

Hard pruning should be minimized now, too. You should be done with pruning spring-blooming shrubs like forsythia and lilacs, because pruning them “after the 4th of July”, as the old-gardener rule says, will be removing next year’s flower buds that start forming now. And once-blooming roses, especially ramblers, should be pruned now, unless their hips are highly ornamental. True ramblers will be sending up large, usually straight and somewhat pliable canes that you want to keep- they produce the best flowers in their second year, so tuck them in and don’t cut them out!

I harp about keeping after weeds, because I have learned the hard way about letting down your guard- you know, “one year to seed; five years to weed!” In combating weeds, it’s good to know your enemy: the control method for an annual weed is usually much different than that for an underground-spreading stoloniferous monster like bindweed. There is a nice online weed guide that is free to download, ‘Weeds of the West’ from the Western Society of Weed Science in cooperation with the Western U.S. Land Grant Universities’ Cooperative Extension Services (mouthful!). For a free reference it’s rather good, but it does call some of our aggressive natives, like yuccas, milkweeds and even sunflowers “weeds,” so reader beware. It is an identification guide; you will need to research control methods elsewhere. Find it here: http://www.wyoextension.org/agpubs/pubs/wsws-1.pdf

Next month I will talk about some of the pests threatening our trees. It’s good to keep in mind that pests usually attack stressed trees preferentially, so keep your trees healthy and well-watered. Trees are some of our longest-lived garden attributes and they deserve to be well-tended at all times. They are an investment and a gift to posterity.