Cornell Farm's Hydrangea

Cornell Farm's Hydrangea

If you didn’t know already, Cornell Farm has a certain claim to fame. No, we’re not talking about our lovingly designed hanging baskets, our Cafe’s fantastic brunch dishes, or even the century-old Monkey Puzzle Tree growing in front of our farmhouse, although those are all good guesses! In this case, we’re actually talking about our exclusive heirloom plants: Grammy’s Hydrangea and Mom’s Lilac. Funny enough, both plants honor the same woman — flower lover and matriarch of the Blatter family, Margaret Blatter. Around here, whether you called her “Mom” or “Grammy” simply depends on which generation you were been born into! Both of these plants have fascinating stories, but today we specifically wanted to focus on the hydrangea that honors Grammy’s memory.

Grammy’s Hydrangea

Long before there was a Nursery and Cafe at 8212 Barnes Road, Ed’s parents Ted and Margaret lived in the farmhouse that is today the Cafe. Sometime in the early 1970s, Ted planted five beautiful hydrangeas just off the front porch for his wife. The exact story of their origin is unknown, but looking at these flowering shrubs, it is clear to see why he was drawn to them: Their oversized "mophead” blooms feature unusually large florets of a striking blue-purple color when grown in our naturally acidic clay soils (more on that in a moment). We have tried to identify if this is an existing variety of Hydrangea macrophylla in the trade, but we've never found one with these exact characteristics. It is likely either an old variety that is no longer widely cultivated, or propagated by cuttings from a unique plant. (Ted, being thrifty, was known to start many plants from cuttings!) Visitors to the Farm have always oohed and aahed over the specimens growing in front of the house, so when Ed and Deby started the Nursery, they decided to propagate this hydrangea and give it a name: Grammy's, after the wonderful woman who loved to sit on her porch and admire her beautiful flowers.

Today, Grammy’s hydrangeas still grow in front of the farmhouse — although, there are no longer five of them — and in the long tradition of “pass along” plants, we offer them for sale each spring so that other gardeners can share in the joy of this unique plant!

Color Shifting

Hydrangea lovers are surely familiar with the unique color changing ability of Hydrangea macrophylla cultivars like Grammy’s. Over time, their flowers may lean more towards pink or blue, which — depending on your gardening ethos — can either be a magical experience or a deeply frustrating one. Ultimately, this color shift boils down to the availability of aluminum in your soil, which is directly linked to soil acidity: Alkaline or basic soils result in pinker blooms, whereas acidic soils result in bluer blooms. The good news is that gardeners can amend their soils to encourage their plants in either direction. For pinker blooms, you can add lime to lower the pH of your soil. And for bluer blooms, consider adding coffee grounds or fertilizing with an organic option fertilized for acid-loving plants to increase the pH of your soil. We even sell a specific "blueing formula" at the Farm for just this purpose!

Most Portland gardeners enjoy decently acidic soils, but interestingly, most potting mixes are actually alkaline. That’s why, although it is truly a blue-purple bloomer, when grown in our typical potting mix, Grammy’s Hydrangea often blooms pink. Once planted out in the landscape, it should return to a nice blue-purple — especially if you give it a bit of help. And this applies to most shade-loving Hydrangea macrophylla cultivars! Unfortunately, if you have a hydrangea that blooms white, no amount of soil amendments will turn it pink, purple, or blue, but if you’re looking for that shade, we have plenty of Hydrangeas at the Farm to add a splash of color to a shadier part of your garden — Grammy’s included!