Mophead Hydrangeas – How to Revitalise a Forgotten Friend

Mophead hydrangea is a hardy ‘do-er,’ which is why we so often take it for granted and confine it to being one of the most neglected plants in the garden. The result is a hydrangea that is ‘leggy,’ twiggy, and incapable of producing its potential masses of large, showy, flowers. The good news, however, is that with just a little attention, we can revitalise our mopheads so they take centre stage in our gardens, and shine as nature intended. Follow the advice below, to make the switch!

There are many varieties of hydrangea, but the one we are most familiar with is the mophead (Hydrangea macrophylla). This is the variety which produces large, flat-topped flowers. Knowing the difference between a mophead and other types of hydrangea is essential when it comes to our first revitalising tip (pruning), so check here to determine whether your hydrangea is, in fact, a mophead. Note: if it’s not a mophead, but the less-common lacecap hydrangea, the same pruning tips apply.

Pruning is essential to bringing an unruly, neglected mophead back into shape and flower production. If you live in a region with mild winters, pruning can be done any time from late autumn through to the start of spring. If you live in a cold region, leave the pruning until after the last frost. If you wish to have some flowers on your hydrangea over summer, pruning and shaping the plant will need to take place over a period of 18 months. If you don’t mind waiting 18 months for any flowers to appear, an immediately satisfying shaping can be made in one hit.

Begin pruning by looking deep into the bush. Snip off, at their base, any stems that have no green bud growth on them (these old, dead, unproductive stems are usually silvered and dry, and snap easily). Next, observe the green bud growth on the remaining stems. Some buds will be fat and in pairs (these are flower buds). Other buds will be small in comparison (these are leaf buds). Sometimes, a flower bud will be paired with a leaf bud i.e. a fat and small bud will be on opposing sides of the stem. If you don’t mind waiting 18 months for flowers, prune all stems back to within 15-20cm of the ground, ensuring some buds remain (they are likely to be leaf buds).

If you want to make sure the hydrangea flowers in the following summer, prune to within 3cm of a pair of flower buds or a flower bud paired with a leaf bud. Cut the remaining stems back to within 15-20cm of the ground, making sure some buds remain (they are likely to be leaf buds).

Now, it’s time to weed and condition the soil. Hydrangea roots grow deeply, so as you weed, don’t be afraid to gently loosen the soil around the base of the plant to a depth of 3-4cm (use a small hand-fork for the purpose). This will allow air into the soil, and help moisture (which hydrangea enjoy) trickle down to the roots. A well as moist soil, hydrangea also favour rich, fertile ground. Provide this by applying a deep (8-10cm) layer of compost, enriched with sterilised animal manure, around the base of the plant, extending out as far as the outer stems. To lock in the moisture, and keep the weeds at bay, top this layer with a mulch of pea straw or well-rotted leaf litter.

Hydrangea thrive in dappled light or partial shade. If your mophead has too little light, trim back at least some of the foliage shading it. If your mophead is growing in dry, sandy conditions, consider digging it up in late autumn or early spring, and moving it to ground with heavier soil. If you don’t have a suitable spot, dig up the hydrangea, create a hole twice the size of its root area, and back fill with 2/3 compost and 1/3 crumbled clay before replanting.

A well-maintained mophead hydrangea has the potential to be a feature in any garden, and the more attention we give these beautiful plants, the more they are admired!