Q.How Do I Care For A Hydrangea In A Pot To Help Survive The Winter?
I have a hydrangea paniculata (I think based upon the descriptions elsewhere on your website). How do I care for it to help it survive the winter and hopefully bloom again next spring/summer? I live in central Texas where it does not get terribly cold for long periods at a time, but we do get freezing temperatures and occasional snow & ice. Thank you.
Just continue watering at ‘dormancy watering levels’ once it goes dormant and drops foliage. Foliage will eventually turn medium yellow or orange and then drop. Maybe it will turn dark green, almost black or turn brown if early frosts hit the Waco area by the 2nd-3rd weeks of November. Blooms should finish color changing and turn brown when spent. The stems will also color change as they harden for winter, turning from green to shades of either gray, brown or sandy colors. All this equates to dormancy and a reduced need (a lesser amount) for water when compared to spring watering levels as there are no leaves requiring moisture. You can keep the container outside or bring it into a garage. Once dormant in the garage, test the potting soil moisture (near the top 2-3 inches but also test to a lesser frequency at the bottom of the container) periodically to avoid letting the soil get bone dry in our dry Texas winters. This winter in Texas is forecasted to have a strong El Niño Southern Oscillation Climate Pattern, when moisture from the Pacific Ocean promotes more precipitation but, there can be dry spells too. Ensure that the container has sufficient/appropriate water drainage holes (drill more holes if the soil at the bottom often tests soggy). Since we do get some winter hail storms in winter here in the DFW Metroplex, I lean towards storing it in the garage to avoid damage to thin stems by large hail stones. Sleet with pellets that are less than 5mm, rarely causes panicle stems to break or bend unless there is a large amount, the plant is not dormant and the stems are still green and pliable). Freezing rain should not bother the panicle stems much but you can protect it if it has flopping branches and if forecasts call for large amounts of freezing rain. While dormant, the shrub will not need sun as there are no leaves needing direct sunlight to photosynthesize. Panicles are typically winter hardy to zone 3. While it can be planted in the ground too, in areas with caliche soil in Central Texas, consider growing it in containers. Depending on the local weather, panicles can break dormancy as early as March in the DFW Metroplex Area but, they do so after Oakleaf and Big Leaf Hydrangeas first break dormancy. No need to worry about flower buds, as usually, there are none at this time. Panicles will break dormancy by setting leaf bud set first and as early as April-May, some early blooming cultivars may then develop flower bud set in early, warm, favorable years. As for existing blooms, you can either never deadhead the blooms or you can deadhead panicle blooms at any time and on any month of the year that you wish. Although panicle blooms will remain attached to the stem until late astronomical spring, they will eventually drop. To deadhead safely without impacting future blooms, prune ABOVE the first pair of leaves (if the stem is leafless, prune the string(s) that attach the bloom to the stem). Similarly, you can never prune stems or you could prune from now until you observe leaf bud set in March. However, consider delaying pruning if the weather forecasts call for warm temperatures plummeting well below 32°F as pruning is an activity that can trigger new stem growth and new foliage growth that will get killed by the sudden drop from the 70s to the teens or lower. Likewise, you can prune later in winter but, during one of our common warm spells in mid-winter, skip pruning until cooler temperatures (soil temperatures below 50°F) arrive. Because some panicle cultivars' stems tend to arch downwards in the summer due to the weight of dense, heavy, wet blooms on thin, green stems or when the shrub is in the middle of the landscape, consider pruning no more than 1/3 of the length of each stem. Generally speaking, woody looking stems are normally stronger than green, thin ones. You can bring the pot outside as soon as all danger of frost has passed, usually by your city’s average date of last frost around the 1st-2nd weeks of April.
