Late frosts can be a disappointment, and can be a real challenge to gardeners. Just as you imagine that warmer spring weather has arrived, a cold snap can threaten tender new growth. You can easily lose the product of some of your hard work during the key sowing season.
However, there are a number of steps that gardeners can take to protect plants from late frosts. Here are some key things to bear in mind:
Avoid Sowing and Growing Your Crops in Frost Pockets
One important thing to think about is where you place your plants outdoors and how this can impact them – especially in spring. Some parts of your garden will likely be far warmer than others.
The terrain and surrounding buildings, and factors relating to sunshine and shade, wind etc. can determine which areas are most likely to experience a frost later than imagined. And determine where frost might linger.
As always, in a garden, the best way to ensure success in your garden is to choose the right plants, and place them in the right locations.
Check the Forecast Before Your Harden Off and Plant Out Indoors-Sown Plants
Forewarned is forearmed. While we cannot always know for sure what the weather will be like, it is important to check the weather forecast before committing to key gardening jobs.
In spring, the weather can change dramatically from one day to the next. So checking the forecast is key. It is especially important before you start to harden off and plant out anything you have sown and grown indoors earlier in the year.
Checking the forecast can also help you to keep abreast of developments, and protect more tender new growth of perennial plants, trees and shrubs in the spring when necessary.
Use a Heated Propagator to Protect Seeds and Seedlings
Sowing and growing means thinking about the temperatures required for both seeds and seedlings. When the weather in spring is unseasonably cold, a heated propagator can help you to make sure that the requisite temperatures are maintained for your annual crops.
A heated propagator will provide gentle bottom heat and help you avoid poor germination rates or seedling death if the weather in spring suddenly takes a turn for the worse. This will not always be essential, of course. However, it can be helpful when it comes to more warmth-loving summer crops like tomatoes, peppers etc…
Invest in a Polytunnel or Greenhouse
If you don’t currently have an undercover growing structure in your garden, investing in one can be a great idea. Having an undercover area, even unheated, is one of the best ways to extend your growing season.
It will give you a little peace of mind, and protect plants at least to a degree from the vagaries of the weather conditions of the season. A polytunnel or greenhouse, even unheated, can remain frost free in the face of late frosts, and make for a smoother and easier spring growing season.
Use a Cold Frame for Tender Seedlings and Young Plants
A cold frame can also be useful, as a half-way house for tender seedlings and young plants making their way from your home to their growing positions outdoors.
This can also be an extra space – not just for hardening off but also for placing tender plants already outdoors when a late frost threatens.
Cover Crops with Cloches or Row Covers
Where crops are already placed out in your garden, cloches and row cover type protection can quickly be added if a late frost is forecast in your area.
These sorts of structures can be purchased. But you can also make your own using things that would otherwise have been thrown away.
Food packaging containers, old plastic drink bottles or milk containers can make good small cloches to protect individual plants during their early stages of growth.
Use Horticultural Fleece or Other Fabric to Cover Tender Growth
Larger perennial plants in your garden, trees and shrubs might also need some protection against a late frost in spring. These plants may have been fully hardy when dormant over the winter months. But tender new growth which emerges in spring may experience frost damage. And late frosts can be particularly damaging to new buds and blossoms.
So to offer some protection, you might consider draping horticultural fleece, or other reclaimed fabric over these plants to give them a fighting chance.
Use Mulches to Cover Bare Soil Between Plants
Mulches can also be important. New organic mulches added in spring will serve a range of functions – adding slow-release fertility, conserving soil moisture, suppressing weeds – and also protecting roots from frost.
Thicker, carbon rich mulches like dried leaves, or straw, for example, can be great for covering areas of bare soil and protecting shallow roots that might be damaged by a late frost.
Sow and Transplant into a Hot Bed
Sowing into a hot bed is another way to keep plants from cold snaps in spring. A hot bed is a structure filled with decomposing organic matter which gives off a gentle heat from below.
Sowing and growing in a covered hot bed can be a great way to protect plants from the cold, and could allow you to get sowing and growing earlier in the year.
Add Thermal Mass Within Your Growing Structures
Finally, if the late frosts are more severe, you might like to take further steps to ensure that any undercover growing structures remain frost free.
One of the key ways to do so is to add thermal mass. Materials with high thermal mass catch and store heat energy, and release it slowly when temperatures fall. This can help to keep the temperatures within a space more stable, and stave off night time frosts in spring.
These are just some tips to help you avoid plant losses due to late frosts, and to ensure that you can grow throughout as much of the year as possible without fearing plant loss due to cold weather.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.
To get in touch, visit https://ewspconsultancy.com.