Hydrangea Care

Caring For Hydrangeas In NZ

With a little bit of attention it is easy to care for hydrangea plants. These guides give the key information for helping produce amazing plants.

How To Care For Hydrangeas

The most important part starts with planting and we have a whole section that discusses that. So, let’s assume your plant is growing well and you want to keep it that way!

Winter is the perfect time for mulching and pruning your plants. Organic matter such as compost or sheep pellets should be spread liberally around the plants and then overlaid with a mulch. The Plant Company has two very good options for mulch. The first is coco fibre matting which is made from the husks of coconuts. It breaks down to become part of the soil within two years. The second is the black plastic matting which will last 20 years or more. In both instances we recommend stones, bark chip, or other similar products be spread over top of the mulch for aesthetic purposes. We do not recommend adding fertiliser during winter as this is better applied in spring so less is wasted. However, adding organic matter is quite okay. Pruning can be aggressive or subtle as you like. Typically, plants are pruned to contain growth and encourage fresh, new foliage. Please refer to the section on pruning to ensure you do this correctly.

Spring is the perfect time for fertilising the plants as they start to bounce into life. The Plant Company has fertilisers which have been specially blended for different plants and in this instance, our fertiliser for acid loving plants or shrub fertiliser will give them the correct boost and keep them fed for 12-months. A suitable alternative is our organic fertiliser which will also keep them well fed but they will require a secondary application in autumn.

Summer is when the plants need regular watering and this should be undertaken daily on the hottest days. Plants that are establishing need particular attention as their root system will not have penetrated deep enough to secure consistent moisture yet. Summer is also the season when spent flowers should be removed to encourage new flowers to grow.

Caring for Hydrangeas in autumn is about keeping the plants healthy and continuing to remove spent flowers. Foliar feeding using a liquid fertiliser can be undertaken during spring, summer, and autumn if you have time but this is not essential if solid fertiliser and/or good amounts of organic matter have already been applied. If you think the plants need an extra boost or have some yellowing, however, a liquid fertiliser won’t hurt.

Check plants for any pest or disease issues during spring, summer, and autumn. If anything is looking a little bit unusual at any time of year, refer to our section on dealing with issues for a solution.

How To Maintain Hydrangeas

Hydrangeas grow best in soil that is rich in nutrients. Therefore, adding compost or other organic mulch to the soil each year is going to pay dividends, as will adding Hydrangea fertiliser. The Plant Company recommends at least 5-6 cm of mulch is applied to help supress weeds and preserve moisture in the soil.

Hydrangeas flower on new growth, so pruning is essential to not only contain the plants, but to also encourage new growth. Generally, the plant is cut back to a crown about 30 cm above ground level each winter. This may seem like aggressive pruning, but it is normal practice, and you should still see buds on the remaining stems. The only maintenance thereafter is to de-head the plants as the flowers fade and trim off any unsightly or broken stems.

Should I Cut Off Dead Hydrangea Flowers?

The aged flowers can make Hydrangea plants less appealing, and The Plant Company recommends the spent flowers are cut off using secateurs. Some articles suggest that doing this can stimulate new growth which can be susceptible to frost. That may be true but remember that the plant will be trimmed in winter so that growth would be removed anyway. Also note that you’d rather have lovely looking plants in the garden than ones covered in dead flowers. It is also worth noting that flowers are produced on new seasons’ growth. Therefore, pruning a plant in winter does not mean you’ll miss out on flowers the next summer.