As we head into spring in the Northeast US, a lot of people ask when the best time to uncover lavender is. At Moore Manor Lavender, we use a lightweight fabric called “Agribon” which helps protect the plants from freezing rain, snow pack, and temperature shifts that we experience in Maine.
The row cover adds a few degrees warmth, and lavender being a heat loving plant will thrive. Even in April we can have snow and cold. In May 2020, we had a snowstorm after we had uncovered and all was well! So basically, if you use a similar material to cover your lavender, you could keep it on up to the end of April.
That being said, where we are, the spring winds blow pretty hard at times and the receding frost pushes the metal pins up. That’s usually the time that we uncover because we don’t want the cover to blow across to the neighbors!
Row cover will block some of the sun from hitting the plants but the protection it gives outweighs the missing sunlight at least until the weather settles some.
So the short answer is , if you’re in an area that’s protected and you want to keep the cover on into April, the plants won’t be harmed and may benefit from the added warmth.
With a little extra care, you can grow lavender in colder climates.
Growing lavender in Maine can be a challenge, but equipped with the right information and doing some simple planning, one can successfully enjoy this versatile landscaping plant. The growing zones for most of Maine are right on the fringe for lavender.
The ideal growing conditions for lavender are that of a Mediterranean climate. Lavender doesn’t require rich soil – in fact , it does best where the soil is a bit lean and the pH is neutral or even ‘sweet’.
There’s one thing that lavender hates more than the cold – that is having wet, not very well drained soil. If you have a heavier soil, like ours in Central Maine you could improve the conditions by adding some grit to the soil – in the form of sand and/or gravel.
If you have fairly level ground and heavy soil, you can create hills or mounds in order to keep the roots out of wet earth.
Different varieties of lavender vary in their tolerance of cold. The Lavandula angustifolia (English Lavender) is one of the most widely grown lavenders. It includes varieties such as Hidecote and Munstead which are more tolerant of winter cold and temperature fluctuations (generally zones 5-8). It can also be grown for culinary purposes as it’s not as ‘piney’ as the french or spanish lavenders.
Lavandins (Lavandula x intermedia) need warmer temperatures and drier ground (zones 6-8). They can be grown to zone 5, so if you’re planning on growing these, you should plan on a lot of winter protection. They put out lots of showy spikes and are very fragrant, although they lack the ‘sweetness’ of the English varieties. Grosso is a very common French lavender variety.It grows up to 36″ wide.
Spanish lavender (Lavandula stoechas) is probably not suitable for the Maine climate unless grown in containers and brought inside. Most need a hot, dry environment (zone 8-9) They do, however, have some of the most interesting colors and flower shapes of the lavenders.
If you plan on growing lavender in Maine, for best results you should cover them once consistent cold occurs. Don’t be in a rush or the mice will make their home along with the protected lavender and ruin a lot of it. Wait until the mice have made their winter burrows elsewhere. Cover with a thick layer of straw, or heavy floating row cover that’s pinned or weighted down. It should be checked periodically to make sure the wind hasn’t uncovered any of it.
Once the weather has warmed, and there’s no threat of a hard freeze the covering can come off. Don’t be distraught if it looks as though the lavender is dead. It takes a bit of warm weather and sunshine for the lavender to start its new growth. By May you should see the your lavender coming to life.
When growing lavender you have lots of choices for varieties. Some grow better in cooler climates than others.
Both Munstead and Hidcote lavender (the two are of Lavandula angustifolia – English lavenders) are good candidates for Northern gardens. They’re easy to obtain, and they have been time tested to be hardy to zone 5
Munstead or Hidcote?
Hidcote lavender has a deeper, violet-blue color for the flowers and the flower head is more compact. The foliage is silver-gray and changes color slightly through the seasons.
Munstead flowers are somewhat ‘looser’ and lighter in color. It’s named for Munstead Woods. Another plus is that it can withstand hot summer temperatures better than other of the English lavenders.
Keep in mind that one of the biggest problems with growing lavender is too much moisture. If your soil is low and wet, try hilling and adding sand and gravel to allow for better drainage. The good news is that they don’t need – or like a rich soil.
Go out and give lavender a try for a border that butterflies and bees love or mixed in with your other flowers.