First thing to do is enjoy the new Hydrangea macrophylla shrub you unexpectedly brought home from the grocery store with the wine and cheese. Of course you already enjoy it, that's why you're wondering about keeping your Christmas hydrangea and planting it out in the yard.
Second thing to do is nothin' much. Keep it/them indoors until the garden warms up in the spring, after last chance of frost. Prune off the unsightly dead flowers. Keep an eye on watering - mine need watering twice a week, which is double (or more) what my house plants need.
Third thing to do is plan ahead for planting out in the spring. Good garden parenting for these big leaf hydrangeas is actually pretty easy. But . . . there are some important things to consider and I'm going to carefully explain them.
Please comment with any questions or clarifications.
7 Tips on How to plant your Christmas hydrangea in your yard or garden:
- Find Partial shade: Morning sun is acceptable, afternoon sun is too harsh in the Deep South, where full shade makes bigleaf hydrangeas happy too. Not only will afternoon sun burn the leaves, it will burn the flowers on most cultivars. If your bigleaf hydrangea is in too much sun, it will balk and not grow much. Shade is crucial. I see hydrangeas growing vigorously in full sun in Cape Cod and it boggles my mind. If you know you live in a climate where hydrangeas do fine in full sun, then go for it.
- Choose moist soil: Hydrangeas like more water than many other garden-variety shrubs and their leaves will "flag" in the afternoon and be one of the first shrubs to signal that the soil is getting dry. I don't water other established shrubs every week, but I water all bigleaf hydrangeas 2-3 times a week. So, if you don't run the sprinkler on a regular basis, maybe pick a spot near a hose or a shady spot that gets a little extra water runoff (but doesn't puddle up for too long - the soil does need to drain within hours after a rain).
- Amended your soil with compost: Work true compost (not topsoil) into your dirt to foster a moist, well-drained base for roots to flourish. Compost both stabilizes the moisture level and improves root growth penetration in hard, compacted clay (a bigger, better root system equates to roots that can find more water and that means a stronger, healthier plant). Compost evens out the moisture in soil, helping it stay more evenly moist when it's dry, rather than fluctuating between dry and wet like clay soils devoid of organic matter typically do in the Deep South.
- Know you climate or growing region of the United States: Most grocery store hydrangea are the tenderest of the macrophylla cultivars - this is why they grow so well indoors for us and in greenhouse production for grocery store sales. The general hardiness range is zone 6 to 10, but I read on the plant tag of a Christmas hydrangea at Kroger the recommendation for zone 8 and warmer, with the caveat of protecting the flower buds from cold damage in zone 7. I think that zones 7-8 and warmer are the safest bet for these grocery store finds, unless it is a named cultivar on the tag and you look it up and see that it's hardier into zone 7 or colder. If you are wondering what growing region you're in, look it up on the USDA Plant Hardiness Zone map. This tip is to help you set realistic expectations for your plant surviving the next winter, not to discourage you from planting it out and giving it a try. You might have a warmer microclimate around you house!
- Some must have cool nights: Conversely, and this is a real kicker because it's counterintuitive to all that cold hardiness info, is that areas of zone 8 with hot nights can sap the life out of a grocery store hydrangea. Many of these guys are that finicky and they like cooler nights, like those found on Cape Cod (a great place to go to see fabulous hydrangeas, by-the-way, and they even have a Hydrangea Festival).
- Time of year you plant out any and all potted grocery store hydrangea: Since we've got climate on the mind, this point follows. If you plant out your glorious grocery store find at the wrong time of year, no matter the cultivar, it will be met with certain disaster. If you've purchased your hydrangea from a grocery store in the autumn or winter, wait until the spring after all chance of frost has past. For me in Zone 8a, that's after April 15th. Remember that your potted hydrangea has lived the cold months pampered indoors and it will be zapped by the cold if you throw it to the elements like that. If you plant it out in spring as temperatures warm, you'll get it acclimated to the outdoors again, and it will harden off in the fall along with the rest of your cold-hardy outdoor plants as temperatures drop and daylight shortens.
- Give it time: This hydrangea was tricked into flowering outside its typical time-frame. It may take a year or two to rest, reset, and readjust to being a normal plant and flowering again.
4 Tips on How not to plant your Christmas hydrangea in your yard or garden (an anti-list to that above):
- Don't plant it in dry shade: Don't plant your hydrangea in the dry shade of an oak. I speak from experience. Yes, I provided the shade a macrophylla needs, but it was parched dry shade. That big old oak hogged all the water. I grew fatigued from extra watering and the plant languished and died - I couldn't outdo the strong oak. A lesson for sure!
- Don't plant it in the wrong type of partial shade: I have planted macs in part shade for sure, but it was morning shade and afternoon sun. I couldn't figure out why my flowers weren't glorious (in fact, they were actually wretched and ugly!). I found out the hard way that bigleaf hydrangea flowers can burn in afternoon sun.
- Don't plant it in a climate that's too cold: In zone 7 and colder, you're taking a risk, but it's not an expensive or dangerous risk, so calibrate your attitude to "adventure," plant out your grocery store hydrangea, protect the flower buds from the cold if you want to, and see what happens. You may have a type that's a little more cold hardy (maybe into 6) or you may have found a protected microclimate (near a building) and have splendid success and have a new shrub to brag about.
- Don't plant out your indoor-store-bought hydrangea in fall or winter: It is not acclimated to outdoors and will freeze to death. That's it.
The intro image at the top shows 'Merritt's White' planted with maidenhair fern. I resisted that temptation, but later purchased these plants: Peppermint Twist (white mophead) and this unlabeled purple/blue H. macrophylla, along with 2 poinsettias. It was a pretty Christmas!
Many of us get excited (especially me) when the flowering billows beckon us away from the cheese display and we have HIGH expectations about bringing them home, enjoying them indoors for a few weeks, then planting them out. A few months later our hopes are often decomposing alongside our once lovely hydrangeas from the grocery store.
I am told that most of these grocery store hydrangeas are varieties that have low cold tolerance and are therefore especially suited to getting to bloom off season in a greenhouse. If you're in a cold area where hydrangeas typically struggle, you may have a harder time getting grocery store hydrangea to survive your winters. Warmer climates (my educated guess is zones 8a and warmer), will likely have better success with them.
This post was written because we are hearing from friends about their disappointment in long-term success with grocery store hydrangeas in their gardens.
Yet, I encourage you to be adventurous! Your Christmas hydrangea may not be the best suited for your climate, but it is always worth planting it outside and giving it a chance in your garden. It may become your most beloved Hydrangea ever! Follow the tips above for likelihood of success.
We'd love to hear from you about your experience with Christmas hydrangeas in the comment section below.