After what feels like the longest and coldest winter I can remember I am dreaming about the arrival of spring. I’m ready to spend the lengthening days basking in wafts of sweet blossom and sunlight that’s starting to feel warm again. But even as the eager shoots of early spring appear, we growers must not forget that freezing temperatures remain a possibility for some weeks yet. Guesstimating when the last frost will occur with even a sliver of accuracy is an imprecise art, yet it is one of – if not the – primary concern for gardeners at this time of year. Frost is felt more intensely in exposed gardens but can be irrelevant for those growing in sheltered spots. The date of the last frost is key for any gardener hoping to grow any of the many plants that aren’t frost hardy and would be damaged or even killed off by below-zero temperatures. Many of the plants that I grow each spring fall into this category, but they also lend themselves to being sown (under cover, on a windowsill or in a greenhouse) up to eight weeks before the last frost. This way they have the opportunity to grow into strong young plants, ready to be put into the ground after the risk of freezing to death has passed. So, given that my garden’s last frost last year fell in mid-April, I’m getting stuck into seed-sowing now. I use modular seed trays to make the most of the space, sowing three to six seeds a module because plenty of crops – beetroot, chard, rocket, parsley, dill, chives, radishes and spring onions – grow happily in a little gang. I single-sow lettuce, as it is easier to harvest when each plant is grown alone, as well as kohlrabi, which needs room to swell around the middle as it matures. Once the tomatoes, chillies and aubergines are large enough, they will be moved out of the heated propagator into pots so they have more room to grow, then I’ll be putting seed trays of basil and shiso in to germinate in the warmth. If I had a bigger vegetable patch, I would also consider sowing seeds for summer cabbages, getting hold of unusual potato varieties and (if I actually liked them) planting some broad beans. Sadly no one has the requisite clairvoyance to predict the exact date that their garden will freeze over for the last time, but through a combination of careful observation of weather forecasts, advice from neighbouring gardeners and keeping note of when it happens every year, it is possible to hazard a reasonable guess. And if you’re new to your growing space or don’t have any friendly nearby gardeners to ask, I find the GardenFocused website useful, as it helps you get your spring growing off to a strong and confident start.