10 Simple Ways To Get Hydrangeas To Bloom

You can safely prune these in late summer, right after the flowers fade and strong shoots form. Remove no more than the top ⅓. Climbing hydrangeas bloom mostly from the top, so prune cautiously. [2] X Trustworthy Source Royal Horticultural Society Leading gardening charity in the U. K. providing resources for identifying, growing and caring for flowers and other plants Go to source Other hydrangeas flower on new growth: feel free to prune back H. aborescens (smooth or wild hydrangea) or H. paniculata (grandiflora) in late winter or early spring. [3] X Trustworthy Source Missouri Botanical Garden Oldest botanical garden in the U. S. and center for botanical research and science education Go to source

Full sun to partial shade: H. quercifolia[6] X Trustworthy Source Missouri Botanical Garden Oldest botanical garden in the U. S. and center for botanical research and science education Go to source , H. paniculata[7] X Trustworthy Source Missouri Botanical Garden Oldest botanical garden in the U. S. and center for botanical research and science education Go to source Partial shade: H. macrophylla[8] X Trustworthy Source University of Georgia Cooperative Extension Division of the University of Georgia focused on research and community education Go to source , H. aborescens[9] X Trustworthy Source Missouri Botanical Garden Oldest botanical garden in the U. S. and center for botanical research and science education Go to source . An area with morning sun and afternoon shade is ideal. If full sun is unavoidable, keep the soil consistently moist. Partial shade to full shade: H. anomala[10] X Trustworthy Source Missouri Botanical Garden Oldest botanical garden in the U. S. and center for botanical research and science education Go to source

Most buds die below -10ºF (-23ºC) without protection. [13] X Trustworthy Source Missouri Botanical Garden Oldest botanical garden in the U. S. and center for botanical research and science education Go to source H. macrophylla is temperamental and can also lose blooms to sudden temperature changes. [14] X Trustworthy Source Missouri Botanical Garden Oldest botanical garden in the U. S. and center for botanical research and science education Go to source Other species are either winter-hardy or do not have winter buds.

As with winter damage, this only applies to H. macrophylla and H. quercifolia. Other species can survive and flower after all but the most extreme winter conditions.

One exception: if, while blooms are growing, the central leaves begin to yellow, throw in some fast-acting fertilizer. [18] X Research source

Give hydrangeas in full sun much more water than ones in partial shade, and even more if their leaves start to droop. [21] X Research source Poor-draining soil can rot your plants’ roots. If a 1 ft × 1 ft (0. 30 m × 0. 30 m) test hole filled with water doesn’t drain within 15 minutes, try amending the soil with compost, peat moss, or similar, or build a raised planting bed filled with loamy soil. If clayey soil can’t be helped, make sure to water less.

Keep the mulch about 3 in (7. 6 cm) from the stems to prevent them from rotting. If you have alkaline soil, try pine needles or bark as a mulch. These make the soil a little more acidic, which hydrangeas prefer. Mulch is often used to insulate roots over winter as well, but unfortunately, it is not likely to save the flower buds on hydrangeas (for old wood blooming varieties).

Test a sample of soil pH with a kit from a gardening center. A pH below 5. 5 encourages blue blossoms. [24] X Research source Lower the pH with compost, coffee grounds, or other organic materials, or using sulfur soil amendments from a garden store. A pH above 6. 5 encourages pink flowers. [25] X Research source Raise the pH by adding wood ash, lime, or some high-pH fertilizers. If your soil is acidic but your flowers aren’t blue, you might need to add aluminum sulfate to the soil.

Treat green, yellow, or brown spots with a fungicide. Ask the staff at a gardening center for advice on local fungus identification and products. [26] X Research source Powdery mildew and black spots are signs that your hydrangea is getting too much shade and not enough air circulation. [27] X Research source Consider transplanting. Many fungi come from excess moisture. Watering in the morning so the plant dries faster can help. If you aren’t able to treat a disease, get rid of the infected plant as soon as possible to prevent the disease from spreading. Dead or dying plants that look badly discolored often aren’t salvageable and can ruin any other hydrangeas you have.