I would like to suggest a little project if you have the space and time. Try growing H. paniculata from seed. Gather the seed in Oct-Nov by placing a dried flower head in a zip-lok bag and shake. Tilt the bag so a corner is down and the dust you see in the bottom is the seed. Clean away all the chaff and store the seed in a cool place until you're ready to sow. Seed germinates in 7-10 days and a first year plant can be 12-14 inches tall depending on how many times you pinch back the new growth. I usually repot 4 times during the first year growing season. I suggest a cold frame the first winter and plant out the following spring. Protect from deer if they are around. The plant may bloom that year, but the key here is to get some growth and structure. Will definitely bloom the next year and third year some plants should grow to 4-5 feet tall. This is very easy to do and the differences in plants is fun to watch. I use Pink Diamond seed exclusively for this and grow some every year. I also am a volunteer grower for an arboretum and we did this with four different seed sources and now have a bed of 55 in their 4th year. Lots of differences in these plants and many mimic the cultivars we are now seeing in the retail trade. If you need a seed source, email me and I can provide you with plenty. Marshall

gfleatham, I've been enjoying the info on various hydrangeas you've been adding and appreciate the accompanying photos. Any chance you'd be willing to add your zone & general location to your profile so that they post by your name automatically? TIA Houzz doesn't make it easy to figure out how, so here are directions: Go to Your Houzz in the upper right of every page, click Edit Profile, and on the left side click advanced settings. Well down the advanced settings page is a blank labeled Climate Zone for Garden Forums along with a link to find your zone. You add info on your state or the nearest large city since zone only relates to average coldest winter temperatures. Then return to the top of the page and click Done Editing.

I think you are playing with fire if you try to do it chemically! What zone are you in and how old is the plant and how big? Can you take some photos? Have you mulched or used ground covers under your bushes? I have more than 40 hydrangeas and grass is not a problem because the root balls are solid enough to keep out grass. If it is really a bad problem, then I would dig up the plant, wash off the roots and pull the grass out from the bottom. Make sure to pull any roots under the root ball and then pop the plant back in the spot where you lifted it. Don't be afraid to dig up a hydrangea - especially for a few hours. Be careful not to cut too many roots but most hydrangeas are pretty shallow rooted and easy to dig. After you replant - be sure to water well and you might have to add some new soil, but be sure to mix it well with the old soil. Mulch the plant well. The mulch will not only keep the soil moist but prevent more grass or weeds from under your hydrangea. Do not add fertilizer at this time - you don't want to encourage new growth that will be killed by the first cold weather.

I would plant it in the ground once it goes dormant OR pot it and keep the pot in the ground during the winter months (this lets you extract the pot should winter become very, very cold unexpectedly). If your winter appears to be unusually cold (long term forecasts are not out yet), bring it into the garage or cover the shrub with lots of mulch to protect it in the rare chance that temps go down enough to risk flower bud damage. Temps around -4C, more or less would start to bother me and I would create a mound around the little shrub. I have planted cuttings of mopheads, serratas and oakleaf hydrangeas of that size with no issues. My concern is usually that temps here tend to go up and down during winter and then they crash so, watch out for similar temperature "behavior". If that were to concern you a lot, feel free to keep it potted in the garage all winter instead (during winter). I noticed some -4C temps (or lower) last winter in your area. December was the coldest month in winter with frequent low temps around -3C thru -6C.