How to care for hydrangeas outdoors in the north during winter?
For netizens who are concerned, a detailed explanation of how to care for hydrangeas outdoors in the north during winter, as well as the winter maintenance methods and precautions for hydrangea cultivation. Let's dive into the details provided by the editor.
Cultivating flowers in the courtyard in the north to survive the winter is a very troublesome task. For flowers like hydrangeas, the winter survival experience online mostly comes from the south, and there is not much experience to draw from in the cold northern regions. Every time I buy hydrangeas, I ask about the plant's cold resistance, and the vendors always throw out a set of data for me to figure out on my own, which has no reference value for whether the hydrangeas can survive the winter safely. Therefore, in my small garden in the northwest, every time I buy a new variety, I have to go through a year of trials to make sure it can survive the winter before planting it in large quantities the following year, which wastes a lot of time. Today, I would like to share my experience of overwintering hydrangeas in the north with temperatures as low as -15 to -20°C, hoping it can be of some help to my northern gardening friends.
We have two purposes for protecting hydrangeas during the winter: first, of course, is to ensure they don't freeze to death. As long as the minimum temperature is not below -20°C and there are bud points of the hydrangeas buried in the soil, they will sprout new branches in the spring of the following year. However, some varieties of hydrangeas that require old branches to bloom cannot be appreciated in spring and summer, and the plants remain small each year, requiring a fresh start every year, which cannot achieve the effect of a blooming garden. The second purpose is to protect all flowering branches to survive the winter, so that each branch can bloom beautifully in spring and summer, which is the result we need. Therefore, our focus today is to protect the entire plant's branches from frost damage.
Conical hydrangeas and tree hydrangeas do not need to worry about overwintering outdoors
Conical hydrangeas and tree hydrangeas have good cold resistance and can survive the winter without protection nationwide, while in extremely cold regions, they need some protection from the cold wind.
Protection measures for overwintering of large-flowered hydrangeas
Large-flowered hydrangeas have the poorest cold resistance, and once the branches are frozen, there will be no flowers to enjoy the following year. Although there are varieties like 'Endless Summer' that bloom on both old and new branches, if the cold protection measures are not adequate and the temperature drops below -15°C, the old branches will still freeze, and you can only rely on new branches to bloom every year. Watching the hydrangeas you've carefully cared for only grow a little each year can be frustrating. But don't worry, with a bit of extra protection this year, you can rest easy.
How to care for hydrangeas outdoors in the north during winter?
If you have young potted plants outdoors, don't rush to repot them in winter. Instead, place a large pot over the small one and cover it with soil. It is recommended to use garden soil or river sand, as these substrates have better insulation properties than nutrient-rich soil. Last year, all the 'Endless Summer' seedlings I planted with coconut bran and peat moss froze to death, but those mixed with garden soil survived the winter, with only the surface branches of the soil layer frozen. You can also fill the gap between the pots with soil or use waste newspapers and old cloth to provide insulation.
This step only protects the roots of the hydrangeas. How do we protect the branches?
Wait until the temperature drops below zero before taking any cold protection measures. Many gardeners are very caring about their hydrangeas and rush to wrap them in bags as soon as the temperature reaches around 5°C. This does not help the hydrangeas' cold resistance at all. When the temperature is above zero, the temperature inside the covering is still high, and the hydrangeas are essentially growing in a small greenhouse, not triggering any self-protection mechanisms. Once the temperature suddenly drops, the temperature inside the bags will drop rapidly, and the hydrangeas will experience a sudden drop from above zero to below zero, which can cause them to freeze to death before they have time to react. Therefore, let the hydrangeas endure the cold weather a bit more before insulating them.
Wait until the leaves naturally turn yellow and fall before taking any cold protection measures. This is a hydrangea variety I photographed this morning, which has been left outdoors and experienced last night's low temperature of -4°C and frost, resulting in slight frostbite on the leaves. At this stage, there is still no need to rush. Wait for a few more days of continuous low temperatures until all the leaves have fallen, then cover them with plastic to block the wind.