How to Grow Hydrangeas: A Step-by-Step Guide

Growing hydrangeas is fairly easy, but to get the best results, you need to follow some basic steps to create the ideal environment for them to thrive. Here are the key tips for success:

1. Choose the Right Location

Hydrangeas are adaptable, but they do best when planted in a location with the proper balance of sunlight and shade. For most types, a location with morning sun and afternoon shade works well. Too much sun can cause wilting, while too much shade can result in fewer blooms. If you are growing hydrangeas with blue flowers, aim for slightly acidic soil to enhance the colour.

2. Prepare the Soil

Hydrangeas love moist, well-drained soil. Test the soil’s pH before planting—hydrangeas tend to prefer a slightly acidic to neutral pH (between 5.5 and 7.0). If you are looking to change the bloom colour of your hydrangeas, you can adjust the soil’s pH by adding amendments. For example, adding sulfur can acidify the soil and turn your blooms blue, while lime can alkalinize the soil and turn them pink.

Before planting, mix in organic matter, such as compost, to enrich the soil and improve its drainage capabilities.

3. Watering and Mulching

Hydrangeas need consistent moisture, especially during hot summer months. Water them regularly, but avoid overwatering, as this can lead to root rot. A layer of mulch around the base of the plant helps retain moisture, suppress weeds, and regulate soil temperature. Mulch also prevents the roots from drying out, which is especially important for newly planted hydrangeas.

4. Fertilizing

Hydrangeas are moderate feeders. Use a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium (such as a 10-10-10 formula) in the spring before new growth begins. Avoid heavy fertilization, as it can encourage too much foliage growth at the expense of blooms. For blue hydrangeas, consider using a fertilizer specifically formulated for acid-loving plants.

5. Pruning Hydrangeas: A Guide to Perfect Blooms

Pruning is one of the most important aspects of hydrangea care. The timing and method depend on the variety you are growing. Here is a closer look at how to prune hydrangeas based on their type:

• Bigleaf Hydrangeas: These bloom on old wood, so it is important to prune them right after they finish flowering in late summer or early fall. Avoid heavy pruning in winter or early spring as this can remove the buds that will bloom the following year.
• Panicle and Smooth Hydrangeas: These hydrangeas bloom on new wood, so they can be pruned back in late winter or early spring before new growth starts. Cutting them back in early spring encourages strong growth and large blooms.
• Oakleaf Hydrangeas: Prune these in late winter to early spring before new growth appears. Like Bigleaf hydrangeas, they bloom on old wood, so minimize pruning to maintain their shape while preserving the bloom potential.

6. Deadheading and Cutting Back

Deadheading, or removing spent blooms, helps improve the appearance of your hydrangea bush, but it is not always necessary for the plant’s health. Cutting back dead flowers can make your hydrangeas look neat and tidy, but if you are trying to preserve the seed heads or plan to cut some flowers for arrangements, you can leave them intact.

7. Winter Care

In colder climates like London, Ontario, hydrangeas need a bit of winter protection to survive the harsh cold. For Bigleaf and Oakleaf hydrangeas, consider adding a layer of mulch around the base to protect the roots from freezing. You can also wrap the plants with burlap or other breathable material to shield them from winter winds and frost.

BEST TIME OF YEAR TO PLANT A LARGE CALLIPER TREE

In climates such as ours in London, Ontario. The ideal time to plant trees in general, is either in the spring and fall. Planting during these times allows trees to establish roots while the weather is mild and before the summer heat or winter cold sets in. During spring, the soil is warming up which helps in root growth, and in fall, the cool weather supports the settling of roots without the stress of hot weather. That being said, trees can be planted in the Summer as well, if planted during the warmer/drier part of the year they generally require extra care, extra watering and maintenance may be required to avoid dehydration.

All newly planted trees do require a significant amount of care and consistent monitoring, over the first full year or two, until they are established.

IF YOU ARE PLANTING IN CLAY. . .

Planting a tree in heavy clay soil requires a bit more work. For best results, dig the hole about 12 to 16“ wider than the root ball. Really scruff up the sides and bottom of the hole to eliminate any smooth surfaces. Plant the tree so that the trunk flare is 2 to 4” above grade – this will allow water to drain away and prevent drowning. Back fill with the previous existing soil mixed with some peat moss and bone meal. The idea is to get the tree accustomed to its new soil–not to over amend the surrounding area.

Trees make our world beautiful and provide us with many obvious benefits – shade, privacy, increased property values, shelter and food for small animals, even a place for childhood tree houses. Besides these obvious benefits, trees also contribute to the health of our planet. They clean the air by giving off oxygen, storing carbon, and recycling moisture into the atmosphere. Trees help prevent soil erosion, help modify temperatures, and act as wind breaks

Companions:

• Plant these lovely vines at the base of shrubs and small trees; they will weave their way through the supporting foliage and extend the season of interest with their showy blooms.

Use the woody structure of Shrub Roses to support the non-clinging Clematis varieties; for instance, grow purple or blue Clematis through a yellow Shrub Rose for a fabulous contrast. Remember that a supporting woody plant will compete with the Clematis for water and nutrients and adjust your culture as necessary.

Reflowering:

• To promote reflowering for late season bloomers during the growing season, the vine can be cut by one-half after the main bloom period.

• Varieties that flower on old and new wood will often throw out a few blooms at the end of the growing season.

Transplanting:

• Young vines may be moved with plenty of soil as long as they are watered religiously.

• Depending on variety, cut back lightly or severely before moving in early spring.

Pruning:

• Dead or damaged stems may be removed at any time.

• Early in the first spring after planting, prune the stems of all Clematis varieties down to the lowest pair of healthy buds. Thereafter, prune to control size and shape or to encourage more profuse bloom.

• Flowering tends to decline on stems that are four or more years old, so it’s a good idea to prune out very old stems periodically in early spring. This pruning helps produce more compact plants with flowers closer to eye level. Sometimes, on older vines, the flowering is confined to a small area at the tops of the stems.

• If you wish, you can rejuvenate old plants by cutting them back severely, to about 18″. Wait until after the first flush of bloom to perform the surgery.

Clematis are divided into pruning groups as follows:

Group I plants bloom on old wood and require no pruning except to control size, in which case prune lightly after flowering back to a pair of healthy buds. Group I varieties include Clematis alpina ‘Stolwijk Gold’ and Clematis montana ‘Mayleen.’

Group II plants bloom first on old wood and then again on new; prune lightly in early spring to shape and remove weak growth and then prune after bloom if desired.

Group II varieties include:

• ‘Alabast’

• ‘Angela’

• Anna Louise™ Evithree(N)

• Arctic Queen™ Evitwo(N)

• ‘Bees’ Jubilee’

• Blue Light®

• Bourbon™

• ‘Carnival’

• Cezanne™ Evipo023(N)

• Cherokee™ Evipo041(N)

• Chevalier™ Evipo040(N)

• Clair de Lune™ Evirin(N)

• Crystal Fountain™ Evipo038(N)

• Dancing® Queen

• Diamantina™ Evipo039(N)

• ‘Diamond Ball’

• Diana’s Delight™ Evipo026(N)

• ‘Dr. Ruppel’

• ‘Edouard Desfosse’

• Empress™ Evipo011(N)

• Fleuri™ Evipo042(N)

• Franziska Maria™ Evipo008(N)

• ‘Guernsey Cream’

• Happy Jack® Purple

• Hyde Hall™ Evipo009(N)

• Ice Blue™

• Josephine™ Evijohill(N)

• Liberation™ Evifive(N)

• ‘Little Mermaid’

• C. lanuginosa

• ‘Candida’

• C. macropetala

• ‘Mon Amour’

• ‘Multi-Blue’

• ‘Nelly Moser’

• ‘Niobe’

• ‘Piilu’

• Rosemoor™ Evipo002(N)

• Royal Velvet™ Evifour(N)

• Sapphire Indigo™

• Still Waters™

• Sugar Candy™ Evione(N)

• ‘The President’

• ‘Vyvyan Pennell’

• ‘Wada’s Primrose’

• Zara™ Evipo062(N)

Group III plants all flower on new growth and can be cut back to 12″ in early spring. This group is ideal for growing through shrubs as all old growth is removed annually.

Group III varieties include:

• ‘American Beauty’

• Amethyst Beauty™ Evipo043(N)

• ‘Arabella’

• Avant-Garde™ Evipo033(N)

• ‘Betty Corning’

• Bonanza™ Evipo031(N) 

• Cassis™ Evipo020(N)

• Chantilly™ Evipo021(N)

• ‘Comtesse de Bouchaud’

• Corinne™ Evipo063(N)

• Edda™ Evipo074(N) 

• Endellion™ Evipo076(N)

• ‘Etoile Violette’

• ‘Fairydust’

• ‘Fascination’

• Clematis florida ‘Plena’

• Clematis florida ‘Sieboldii’

• Guiding Promise™ Evipo053(N) 

• C. x jackmanii ‘Superba’

• Juliane™ Evipo049(N) 

• ‘Madame Julia Correvon’

• Marta™ Evipo071(N)

• ‘Morning Star’

• Clematis paniculata 

• Parisienne™ Evipo019(N) 

• Peppermint™ 

• Picardy™ Evipo024(N) 

• ‘Pink Fantasy,

• ‘Pink Mink®

• Pistachio™

• Samaritan Jo™ Evipo075(N) 

• ‘Summerdream’

• ‘Sunset’

• ‘Sweet Summer Love’

• Tekla™ Evipo069(N) 

• ‘Tie Dye’

• Clematis x triternata ‘Rubromarginata’

• Vienetta™ 

• ‘Ville de Lyon’

• Wisley™ Evipo001(N)

End of Season Care:

• Plants may be mulched, but take care to keep mulch material away from the crowns and stems of the plants.

• Check to make sure that the vines of Group I and II plants are tied securely to supports to withstand winter winds.

Calendar of Care

Early Spring:

• Fertilize with 5-10-10 when new growth reaches two inches.

• If you need to move a plant, transplant young vines now.

• Wait until new growth appears before removing dead or damaged stems and before pruning as required by variety: leave Group I Clematis alone; prune Group II plants lightly to shape and remove weak growth; cut Group III varieties back to 12 inches above the ground, or higher if you desire taller vines.

• If this is the first spring after planting, prune stems of all varieties down to the lowest pair of healthy buds to encourage strong growth and new stems.

Mid-Spring:

• Continue feeding every month, alternating 5-10-10 with 10-10-10.

• Plant annuals at base of plants if unprotected by flat stones to allow for a cool root zone.

• Gently tie vines to supports as they grow.

Late Spring:

• Mulch if desired but keep material away from crowns and stems.

• Water thoroughly if season is dry.

• Cultivate around vines with care as physical injury will cause wilting and death of injured stems.

• Continue to guide new growth by tying to supports as needed.

• Lightly prune Group I Clematis immediately after flowering to shape the vines if needed.

Summer:

• Watch for signs of fungal wilt and remove and destroy affected plant parts if it occurs, then sterilize pruners with bleach solution.

• Group II Clematis may be pruned back by one-half after main flush of bloom to encourage strong growth and new flowers.

• Continue to water if conditions indicate.

Fall:

• Check to be certain that the vines of Group I and II varieties are tied securely to supports to withstand winter wind and snow.

• Mulch if desired, keeping material away from the crown.

• If the season is dry, water well and deeply.

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