Hydrangeas

Hydrangeas are a large family of which the most famous are the ones with big pompons. They come in many species and varieties. Whether they are bushy, climbing or shrubby, hydrangeas will continue to amaze us!

A vast family

Some people make the distinction between "hydrangeas" and "hydrangeas", but they are one and the same perennial plant belonging to the Hydrangea genus. The term "Hydrangea" is simply the common name for this well-known plant. There are many species in the Hydrangea genus, each with its own particular characteristics.

Hydrangea macrophylla

This is the most common plant of the genus, the one we call "hydrangea" in common language. This shrubby species with large leaves can reach up to 2 meters in height and spread when the conditions are favorable, that is to say in fresh, humus and acid soil. It is recognizable by its big balls of blue, pink or white flowers carried by rigid but hollow stems. This species blooms on the branches of the previous year, a late pruning or a frost can then compromise the bloom of the year.

Hydrangea petiolaris

This climbing species of strong development is ideal to cover a support along a wall. It bears beautiful white inflorescences in spreading domes. This hydrangea can reach 15 meters in height, its leaves take on a beautiful golden color in the fall; it is an outstanding ornamental subject.

Hydrangea quercifolia

As its name suggests, this hydrangea is remarkable for its large oak-like leaves that take on flamboyant hues in the fall. It is ideal in beds or pots but should be avoided in humid soil as it would then be too sensitive to root rot.

Hydrangea paniculata

Easy to grow and very hardy, this very vigorous species is gaining more and more followers charmed by its conical inflorescences of cream color turning to pale pink. This hydrangea supports very well a sunny exposure.

Hydrangea involucrata

Very compact (1 m high) the Hydrangea involucrata is well suited to the center of a bed or in pots. It likes a fresh and humid soil where it will display from July its rounded corymbs with small blue flowers surrounded by bigger single to double, white, pale blue or pink flowers which give it its nickname of "Hydrangea with peony flower".

Hydrangea arborescens

This arborescent Hydrangea is a vigorous species, easy to cultivate because it tolerates most soils and exposures. It is a large suckering shrub producing large inflorescences in the form of very spectacular white balls. This hydrangea can easily reach 3 meters in height.

Lilacs, growing tips

Unknown species of lilac

The lilacs that we usually see in gardens are a variation of a single species, Syringa Vulgaris; only the flower changes: single, double, pink, white... The leaves and the port of the shrub are always the same.

However, there are 22 species such as, for example, the parsley-leaved lilac, the Afghan lilac, the laciniate lilac, meyeri palibin, or the lilac oblata which is the first to flower. To these 22 species, we must add the many varieties.

As for Syringa Vulgaris, the common lilac, there are hundreds of varieties. They are preferred by gardeners, which is quite surprising considering that the other species have the same characteristics.

Lilacs of any kind are plants that grow on most soils, are very hardy, have a fragrant bloom and are very flowering. The sizes can vary: some varieties are of medium size (2 meters high), while others do not exceed 1 meter in height.

The flowering of lilacs

All lilacs bloom in spring but some are earlier than others. If you make a good arrangement in your garden, you can get 3 months of lilac bloom.

The earliest is Syringa oblata, which blooms in late March and has single white flowers. It grows up to 2 or 3 meters high. Later, the Preston Lilacs, Canadian hybrids, bloom at the end of May. As for Syringa reticulata, the tallest of the lilacs (6 meters high), it blooms at the beginning of June.

Conditions for growing lilacs

Lilacs, whatever they are, are very undemanding plants as to the nature of the soil, which resist to very cold temperatures, between -30 and -40°C (we must remember that they are almost all native to the Himalayan hillsides).

Lilacs are full sun plants. Shade is detrimental to flowering. On the other hand, because of their origins, they appreciate a certain coolness of the soil. In the South, watering may be necessary during the summer. Leaves that hang down will be the signal of a lack of water.

Pruning lilacs

Some say that lilacs are pruned in clumps, implying that lilacs do not need pruning. However, it does tolerate pruning very well, provided that it is done just after flowering, so as not to remove the flower and to obtain a bloom the following year. A pruning done in winter suppresses the bloom the following spring.

If you have old lilacs, a rejuvenation pruning can be done, but in this case, the next bloom will be compromised. To lessen the trauma, it is advisable to prune in two times: cut large branches very short, but only every other one. The following year you will finish the pruning.

Cultivation of lilacs in pots

The culture in pot is possible on the condition that you bring him food and water regularly.

Proteas, growing tips

The Proteaceae family

Proteas are from the proteaceae family, one of the oldest families in the world.

The plants of this family are native to Australia and South Africa. In South Africa, you will find mostly proteas, leucospermums and leucadendrons, while in Australia, you will find more plants belonging to the genera banksias, telopeas and many grevilleas.

The proteas of South Africa bloom in spring and fall, while the protaceae of Australia can bloom in winter, spring and fall.

None of them bloom in summer; this is their vegetative rest period. It corresponds to the winter season in their country of origin.

They all have an evergreen foliage.

Tips for growing proteas

Most of the proteas from South Africa require full sun, a poor, acid and drained soil. Their hardiness is within a temperature range of - 4°C to - 10°C.

The proteaceae of Australia are a little more rustic (- 10°C / -12°C). Some of them, such as the telopeas, appreciate more a mid-shade or even a shade exposure.

Pruning advice for proteas

South African proteas must be pruned.

Indeed, it is the new branches which carry the flowers. To force the plant to branch out and produce new branches, it is necessary to prune the old ones.

As for the Australian proteas, it is rarely necessary to prune them, because the branching occurs naturally from the faded flower buds.

Who can host proteas?

Brittany offers ideal growing conditions for proteas; it is neither very cold nor very hot. If you live on the French Riviera, you can also try growing them, although your plants will suffer from the summer heat.

Diseases of proteas

Proteas are little attacked by pests but on the other hand, they are very sensitive to a pathogenic fungus: the phytophthora.  To prevent this contamination, it is usual to spray, when the weather is hot (a condition that favors the development of the fungus) a preventive systemic fungicide, Aliette (non organic), widely used for the protection of conifers.

To discover

• Telopea speciosissima, commonly called Waratah, emblem of Australia
• Protea cynaroides 'Little princess', which forms a pretty small shrub, 1 m high and 80 cm wide.

Planting and maintenance of Indian lilac

The Indian Lilac is a beautiful shrub that is covered with clusters of flowers all summer long. Its foliage turns flamboyant in autumn and it remains decorative even in winter thanks to its cinnamon-colored bark that peels off.

When to plant the Indian Lilac?

The Indian lilac (Lagestroemia) should be planted preferably in autumn, or in spring in the coldest regions. Choose a hardy variety, some of them can withstand temperatures of -10° C for a short period of time and once well established.

How to plant the Indian Lilac?

• Choose a sunny spot sheltered from the prevailing winds. The Indian lilac appreciates a rich and humus soil and a well drained soil.
• Soak the root ball in a large basin of water at room temperature to hydrate it before planting.
• Dig a hole twice the size of the root ball in all directions.
• If the excavated soil is poor, replace half its volume with good commercial potting soil and compost.
• Scratch the bottom of the hole and mix a bit of crushed horn into the soil which will help the plant to restart.
• Form a small mound at the bottom of the hole with the prepared soil.
• Place the roots of the shrub on this mound, adjusting the height so that the collar is flush with the soil.
• Fill in and pack down.
• Water abundantly and add some soil if necessary.

Pot culture: plant the Lagerstroemia in a large container (minimum 60 cm of sides and depth) with a hole at the bottom. Provide a layer of clay balls equal to 20% of the volume of the pot to ensure good drainage. Plant your Indian lilac in a mixture of good potting soil and compost with a shovelful of crushed horn powder. Water.

Maintenance of the Indian Lilac

For the first few years after planting, water copiously about twice a week in summer. Scrub manure at the foot of the tree in October. Apply a granular organic fertilizer in April and again in July to support the abundant flowering.

Prune the Indian Lilac in March by cutting back the previous year's shoots by half to induce the appearance of young flowering shoots. Take advantage of this to remove the dead wood and remove some branches that cross in the center of the shrub.

Mulch the base and install a winter cover in the coldest regions to protect the Indian lilac from freezing in winter.

Be careful: pay particular attention to the subjects planted in pots, as the mixture dries out very quickly. In summer, watering should be sustained. A contribution of liquid fertilizer for flowering shrubs every 15 days from May to August will be welcome.

Planting, pruning and maintenance of lilacs

With its unforgettable springtime fragrance and clusters of delicately colored flowers, the lilac is one of the most essential shrubs in the garden. From planting to maintenance, focus on this plant that will accompany you with its sweet fragrance for many years.

When to plant lilac?

The lilac is an easy to grow shrub that can be planted over a long period from September to May, avoiding of course periods of heavy frost.

How to plant lilac?

The lilac is a versatile shrub that can be planted as an isolated specimen or in a hedge or bed. If you plant it in groups, remember to space each foot 1.5 m apart. The lilac appreciates rich, moist soil and tolerates limestone well. Choose a sunny spot to install your lilac.

• Soak the root ball in a basin of water at room temperature to hydrate it before planting.
• Meanwhile, spade the soil to aerate it and remove stones and weeds.
• Incorporate decomposed manure and compost into the soil.
• Dig a hole twice the size of the root ball in all directions.
• Scratch the bottom of the hole and add a handful of ground horn.
• Pour a little prepared soil into the bottom of the hole and add good planting soil, calculating the height so that the neck of the plant is flush with the ground.
• Place your lilac plant in the center of the hole and fill it in by packing the soil around the foot.
• Water abundantly.

How to maintain the lilac?

Water your lilac regularly during the summer and the months following planting to ensure a good recovery. In autumn, amend the soil at the foot of the lilac with composted manure to nourish it and prepare for abundant spring flowering.

Very resistant if cultivated in an optimal way, the lilac will not be attacked by any parasite, it is very hardy but late frosts can sometimes damage the young shoots.

Remember to remove the faded flowers to avoid the formation of seeds which exhausts the plant.

The lilac does not need any particular pruning operation, however if you want to prune it, proceed just after flowering by removing the dead wood and the spindly or crossing branches. If you prune too late, your lilac will not flower the following year. Older plants can be rejuvenated by pruning drastically to about 20 cm from the ground. Do this in the fall if it is really necessary, the lilac will form a clump capable of flowering two years later.

Frequently asked questions about lilac

Its incomparable fragrance is associated with the long-awaited arrival of spring. Purple, pink, white or bluish, its clustered inflorescences attract all pollinating insects. Easy to grow, the lilac is one of the must-have shrubs in a garden!

To which botanical family does the Lilac belong?

The lilac belongs to the genus Syringa which has about twenty species and is part of the Oleaceae family.

Syringa vulgaris is native to the Orient as is Syringa persica, the Persian lilac, a lesser known but equally fragrant species. The lilac is a deciduous shrub that can reach 1.5 to 7 meters in height depending on the species and varieties.

How to water the lilac?

Once well established in the ground (more than 3 years old), lilacs can withstand a few dry spells, especially when it comes to the Syringa vulgaris type, as the cultivars are more sensitive to water shortages.

In the years following planting, the soil must remain cool throughout the summer. Mulch it copiously to preserve its humidity. Beware of winter drought in southern regions on recently planted plants!

In pots, the substrate should never dry out completely during the summer season, but should not remain soggy. In winter, reduce watering to the strict minimum.

How to grow lilac in the ground?

Lilac is not a difficult shrub to grow as long as the soil is well drained. Stony and chalky soils do not discourage it, on the contrary! It appreciates a very sunny exposure but can tolerate half-shade in southern regions.

The typical species Syringa vulgaris tolerates drought much better than its cultivars, which need always fresh soil, especially in the heart of summer. A thick mulching of the foot will help to maintain it.

How to propagate lilac?

The easiest way to propagate suckering species is to take the shoots in autumn, by detaching them from the mother plant with a spade and a pair of secateurs. You can then replant them in another part of the garden immediately and water them regularly if it does not rain enough to ensure that they take root.

Cutting is easy to do. Heel cuttings or T-cuttings are the most suitable techniques for lilacs. This type of cutting is done in summer.

Take an end of a semi-lignified secondary stem carried by a healthy branch of which you will keep a small part (bark for the heel cutting, section of two centimeters for the cutting in 'T'.

Place the cutting in a bucket containing a mixture of potting soil or sand, or even a commercial 'Special seedlings and cuttings' substrate after having left only the two leaves at the top. Water and place the cutting in the shade in a place sheltered from the wind.

As soon as the first signs of recovery appear, repot in a larger pot and in a richer substrate. Keep it until the fall of the following year, when it will be time to plant your lilac in the garden!

How to plant lilac in a pot?

Potting lilacs is best done after they have bloomed in late spring.

• Choose a container or a pot of at least 40 cm in all directions with a hole in the bottom.
• Provide a layer of draining material at the bottom of the pot (pozzolan, gravel, clay balls, etc.) to ensure good drainage, as the lilac hates having its roots constantly soggy.
• Make up a mixture of potting soil, garden soil (if it is calcareous, it is even better), river sand and compost to install your shrub.
• Leave the neck of the plant 3 cm below the top of the pot.
• Pack well around the base of the plant.
• Water and adjust the height of the substrate if necessary.

How to plant a lilac in the ground?

Choose a sunny spot to plant your lilac.

• Moisten the root ball in a basin of water at room temperature after removing it from its container.
• Dig a hole twice the size of the root ball in all directions.
• Add well-decomposed compost and organic fertilizer pellets to the soil, and add a little fireplace ash if you have it. If the soil is very clayey, mix in a few shovelfuls of river sand.
• Pour this mixture into the bottom of the hole and adjust the height of the soil so that the neck of the plant is just below the soil surface.
• Backfill, keeping the shrub upright.
• Pack well around the base.
• Water copiously.
• Form a basin to retain water at the foot of the lilac.

How to prune a lilac?

Future flowering will take place on the previous year's shoots, so pruning should be done just after the spring flowering and in a delicate manner!

In addition to the pruning of wilted flowers (Cf. 'Should we cut the wilted flowers of the lilac?'), a pruning of the aerial parts can be considered but only on the subjects already well established (3 or 4 years).

The purpose of this pruning will be to clear the center of the shrub by cutting off dead or crossing branches in order to let in light and to favor natural ventilation.

If an old lilac becomes less floriferous and bald at the base, it will be possible to perform a drastic pruning of all the aerial parts. Cut the dead and oldest branches short. Cut back the others to 30 cm from the ground. This pruning should only be done in winter during the resting period, well before bud break (opening of the buds). Obviously, flowering will be compromised in the spring, but the old lilac will find a new youth.

Some species and varieties have a tendency to spread by suckers. You can prune them as close as possible to the mother plant, but be aware that this type of pruning stimulates the appearance of suckers.

Do I have to cut off the wilted flowers of the lilac?

This is not a requirement on non-remontant varieties, but it is possible to cut off spent inflorescences for aesthetic reasons. Prune above the first large bud just below the flowering stem. Cut at a sharp bevel away from the bud so that water does not linger on it.

Prune remontant varieties (which rebloom in autumn) systematically after flowering by simply cutting off the stalk of the cluster, this will stimulate the second flowering, as the shrub will not spend its energy on producing seeds.

Is it possible to grow a lilac in a pot?

It is quite possible to grow a lilac in a pot, so choose a low-growing variety such as Syringa meyeri 'Palibin' with pink flowers, S. julianae 'Red Pixie' with purple flowers, 'Bloomerang Pink' a hybrid with remontant pink flowers, or for those who like bluish shades Syringa persica 'Laciniata'.

In pots, it is important to be particularly careful about watering, as the substrate should never dry out more than 3 cm on the surface. Be also careful with a too hot exposure in the southern regions, prefer to place the pot in a shady area during the hottest hours of the day in summer.

Remember to feed the lilac with a liquid organic fertilizer (following the manufacturer's advice) or a mixture of ground horn and dried blood every 3 months from March to September.

Is the Indian lilac in the same genus as the common lilac?

No, the Indian lilac (Lagerstroemia indica) is part of the genus Lagerstroemia and of the Lythraceae family. As its Latin name does not indicate, it is native to China and not to India as one might think.

It is a tree which can reach 3 meters in height for as much of spread. It blooms in summer and is not hardy unlike the classic lilac.

Is the lilac hardy?

Yes, all species of lilac are hardy up to -15°C or more in well-drained soil, so it can be introduced in most gardens.

Attention: the Indian lilac (Lagerstroemia) which is not part of the genus Syringa (Cf. 'Is the Indian lilac part of the same genus as the common lilac? ') is not hardy, it will only be planted in the mildest regions.

When is the best time to plant lilac?

The beginning of autumn is the best time to plant the lilac, however winter and early spring are also other opportunities for planting.

Be careful, if you plant lilac in the spring, to wait until the end of the flowering period and be particularly vigilant about watering throughout the summer.

What are the most interesting species and varieties of lilac?

Among the numerous species and cultivars, here is a small selection which is not exhaustive:

• Syringa Vulgaris otherwise known as 'French lilac' or 'common lilac' comes in multiple cultivars selected for the color of their flowers. The typical species bears panicles of lilac colored flowers very perfumed.
• Among the cultivars, 'Souvenir de Louis Spaeth', 'Prince Wolkonsky' and 'Charles Joly' present clusters of purple flowers, 'Captain Baltet', 'Double bleu' and 'Firmament' decline beautiful shades of blue, 'Belle de Nancy', 'Belle de Moscou' or 'Katerine Havemeyer' resplendent in pink, while 'Madame Lemoine' remains the undisputed star of the white lilacs.
• Syringa patula 'Miss Kim' is a graceful and small (1.5 m in all directions) cultivar, ideal for small gardens. The clusters of flowers are full of small, deliciously scented pale pink flowers that maintain a very airy feel.
• Syringa meyeri 'Flowerfesta White' forms a bush of 1,25 m in all directions. It is ideal in pots or in city gardens. The fragrant, white spring flowers are repeat flowering in September/October. Note that this recent obtention is available in blue and pink.
• Syringa microphylla is an interesting species for its compact bushy habit (2 m in all directions) and its long-lasting (April to June), sometimes remontant, flowering from September to the end of October. Superba' is particularly easy to grow and is covered with pink flowers.

What are the most common diseases of lilac?

Very vigorous, lilacs are only really affected by fire blight, which manifests itself as black stained leaves and blackened shoots. Cut off all affected parts down to the sound wood, water with a decoction of garlic and spray with horsetail manure.

What are the main pests of lilac?

Otiorhynchus, cantharides and lilac moth (a caterpillar) are the most common pests. Spray fern purin every 15 days to prevent them.