What to Do With a Mulberry Tree in May – For an Impressive Harvest of Juicy Summer Fruit
Mulberry trees are easy to care for once established, but these tasks are essential to help them thrive in the summertime
Often described as low-maintenance and easy to grow, mulberry trees can be a wonderful addition to your garden. In May, however, they require careful upkeep: you'll need to fertilize, water regularly, and avoid hard pruning your mulberry tree before it starts to bear fruit.
Steady moisture and balanced nutrition is crucial for mulberry trees at this time of year; it's what helps them to produce lush foliage and bigger berries. The fruit itself should start to appear in late June – though it's worth noting that mulberry trees can take up to 10 years to fruit, if planted from seed.
1. Prioritize Steady Watering
Although they are relatively drought-tolerant fruit trees once established, mulberry trees require steady watering after planting, and during hot spells.
'Aim for steady moisture rather than frequent light watering, because mulberries respond best when the root zone stays evenly damp but never waterlogged,' summarizes gardening and horticulture expert Patrick Martin.
Use a soil moisture meter (like this one from Walmart) to monitor newly-planted mulberry trees, checking at least twice a week.
'Feel the soil about 5cm down, and if it's dry at that depth, water thoroughly with roughly 10-15 litres – applied slowly so it soaks in rather than running off),' advises Patrick.
'For established trees, watering is usually only needed in dry spells, but when you do water, go deep. One slow soak of around 20-30 litres every 10-14 days is typically more effective than smaller amounts more often.'
Patrick Martin is a horticulture specialist with more than 15 years of hands on experience managing productive gardens and running Frantoio Grove, a working olive farm focused on sustainable growing and soil health. He specialises in soil improvement, climate resilient planting and sustainable techniques that help gardens thrive with less intervention. His work spans edible growing, plant health, seasonal maintenance and practical solutions for common gardening challenges.
2. Start Mulching
Mulching is a brilliant way to lock in soil moisture during warmer weather, and May is an ideal time to start.
'Mulching is an important maintenance job for any fruit tree, and mulberries are no different,' confirms Drew Swainston, Content Editor at Homes & Gardens. 'If you haven’t got around to mulching your mulberry tree yet, make spring the time to do it.'
You can use pine bark mulch, which you'll find at Amazon, or organic compost, which you can pick up at Home Depot.
'Adding a 2-4 inch layer of organic mulch around your mulberry tree will suppress weeds and retain moisture in the soil, reducing how much you need to water it when the fruits are developing,' explains Drew.
'Mulch a good-sized circle around the tree, but make sure to leave a four-inch gap around the trunk. Never pile mulch against the tree’s trunk, as it can cause rot.'
Drew has worked as a writer since 2008 and was also a professional gardener for many years. As a trained horticulturist, he worked in prestigious historic gardens, including Hanbury Hall and the world-famous Hidcote Manor Garden. He also spent time as a specialist kitchen gardener at Soho Farmhouse and Netherby Hall, where he grew vegetables, fruit, herbs, and cut flowers for restaurants. Drew has written for numerous print and online publications and is an allotment holder and garden blogger. He was shortlisted for the Digital Gardening Writer of the Year at the 2025 Garden Media Guild Awards.
3. Don't Forget to Fertilize
Spring is also the time to start fertilizing your mulberry tree – so if you haven't already, you'll want to create a feeding routine in May.
'May is a sensible time for a moderate, balanced feed that supports both leafy growth and fruit development,' says Patrick. 'A balanced slow-release fertilizer, used at the label rate, is usually sufficient.'
Try 10-10-10 organic plant food, which you can buy from Amazon – and watch out for nitrogen-rich fertilizers, which can be detrimental to fruit trees.
'High-nitrogen feeds can encourage lots of leaf at the expense of fruit, and they can also make growth more prone to pests and wind damage,' Patrick explains. 'I would avoid heavy applications of fresh manure, alongside nitrogen-rich lawn fertilizers.'
4. Avoid Hard Pruning
Knowing when to prune fruit trees is crucial, and mulberry trees should mostly be left alone at this time of year.
You'll still need to remove dead branches to prevent bug infestations and diseases, but make sure to work carefully, using sharp, reliable tools (such as the Felco F2 pruning shears, which you'll find at Home Depot.)
'In May, keep mulberry pruning to essentials only,' advises Patrick. 'Remove dead, damaged or rubbing branches, plus any obvious suckers from the base. Make clean cuts back to a suitable junction and keep tools clean, especially if you are removing suspect wood.'
If you're unsure of how to prune fruit trees like mulberries, restraint is key in the springtime.
'Mulberries can bleed sap heavily if cut at the wrong time, and removing too much now can reduce this season’s crop because you may cut off fruiting wood or stress the tree during fruit set,' says Patrick. 'Save shaping, size reduction, and more structural pruning for winter dormancy.'
5. Try Propagating
You might need to hold off on heavy pruning, but if you've been tempted to take mulberry tree cuttings, May is a great time to get stuck in. Late spring or early summer is when most gardeners take softwood cuttings, since new stems are still young and flexible.
Using a pair of pruning snips (like these from Amazon), remove fresh, green stems at a length of up to 8 inches. Strip each one of foliage – leaving just two leaves at the top of each stem – before dipping the bottom inch in rooting hormone powder, which you can buy at Walmart.
Then, simply plant the cuttings in a well-draining potting mix, place them in a partially shaded location, and mist them regularly to support root growth, which should take around 6 weeks.
If you're in need of more mulberry tree advice, you can check out our guide to growing mulberry trees in pots, or find tips on getting a mulberry tree to fruit.
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