Temperennials

I spend a lot of time counseling people on what to plant and how to lay things out, especially on weekends when I'm working at Merrifield Gardens. I have to be receptive to what they have emotional attachments to. Quite often it's peony plants passed down from grandma, or a rose from a dear aunt. It's a work around and I have no problem with it because I have my own emotional attachments, enough to fill 5 acres - I'm sure. Fortunately I can live vicariously through other peoples gardens, not actually owning all of those tree peonies (as 1 example), but tending to them. 

So recently I was thinking about my own plant baggage, like what must I have in my summer garden? It struck me that so much of what I like fits into the category of temperennials. The term is not new and I assume its from a mix of tender perennial or temporary perennial. Long and short it stands for plants that are either border line in their hardiness or just flat out tropical, perennials in their own tropical climate versus true annuals, which die after producing seed. Now we live in a pretty moderate climate, getting warmer as each year passes. We do have freezing temperatures in winter, but it's nothing like it used to be. I remember when crape myrtles would freeze to the ground in Loudoun County, sometimes even in Fairfax county.

Many of these temperennials flower from spring to fall and come back in spring. A pretty good deal when you think of hardy perennials that flower for a matter of weeks (6 is average). In the last few years I have seen dahlias return with a certain degree of regularity. I hear the same with cannas and I can definately say that my Salvia 'Black and Blue' has come back for 3 years and is now 7 feet across. Agastache rupestris is the only variety of agastache that's returned and it's done so for 4 years. All of these flower the entire summer. I'm beginning to think that its time to try various verbenas and go back to growing Salvia farinacea selections and snapdragons, all of which fit in the category of temperennials.

Salvia 'Black and Blue' 

Agastache rupestris

I will note that fall planting is not ideal, the winter survivers are planted in spring when they can develop a good root system before winter hits. It's also good to have a protective spot, say a eastern or south eastern exposure. Given that, incredible things can happen. During our super mild winter I had a cordyline return, and dichondra has been in the garden for 3 years, sprouting here and there from starts left from the year before. 

So if your ready for a little experimentation, I think a few temperennials may turn out to be perennials that bloom all summer, and that's a win-win for gardeners.

Comments

[Enid Adams]

Hey Karen, you instilled a love of salvias and hyssops in many of us from Windy Hill days. Lucky you to have agastache rupestris coming back! One of the summer series made it through winter and early spring but then was gone. I now have to decide whether to plant these 3 salvia black & blues in the ground, or in pots, to try to winter over. Good drainage seems to be key, but do they need SOME water when they are dormant? I'm guessing s. Mexicana Limelight is totally tropical and wondered if I might winter the pot over in the cellar where it never freezes but is dark. Sage advice? Enid

[Karen]

You know Enid, Salvia 'Limelight' is special on so many levels, if it doesn't freeze before it flowers. I don't think it will winter over even in a micro-climate. You have nothing to lose by putting it in the cellar, so go for it, but consider cuttings if you have stems that will give you that. As for the Salvia 'Black and Blue', with 3 you can try 1 outside (in a good spot), and 1 in the cellar and 1 inside. I am going to cut it back by half next year because it grew way too large this summer. The hummingbirds loved it!