The best times to plant

Planting period: a key to your garden's success

Planting in midsummer heat at a time when soils become dry and hard and when plants spend a great deal of energy producing flowers and leaves, or conversely in winter when the soil is cold or even frozen is clearly not a good idea. Each season has its advantages and drawbacks, and in the garden, spring and autumn, with their (normally) regular rains, prove to be the most favourable times for plants to establish themselves: not only will the rains promote good rooting, but the soil gradually warms in spring, and remains warm enough in October and November before the first frosts to allow the plants to settle in.

Spring and autumn rains are very useful when planting a young plant

What to plant and when in the year?

Key concepts to remember are the difference between evergreen plants and deciduous-leaved plants, as well as the hardiness of plants—their ability to withstand colder temperatures to varying degrees.

Spring plantings

They are advantageous, as the soil begins to warm up in the regions south of the Loire, and adventives are still relatively sparse, making soil work easier. It’s often a season when we feel a fierce urge to plant everything in sight! So we can indulge ourselves without fear, provided we water the plantings well from April when rainfall becomes scarce.

⇒ Affected include :

–frost-prone shrubs and climbing plants, at the edge of hardiness
–bulbs that flower in summer and autumn (Dahlias, crocosmias, gladioli, nerines…)
– evergreen shrubs and frost-sensitive climbing plants
– bamboos
– toutes les annuals
– et évidemment les légumes annuels (tomatoes, courgettes…) qui seront récoltés en automne.

→ Read also: What to plant in spring? ; When to plant summer bulbs?

Autumn plantings

These are essentially the ones we would recommend for the majority of plants (except frost-tender ones). Deciduous plants go into a resting phase, which we call dormancy. The famous Sainte-Catherine saying advises planting around 25 November… We actually plant earlier, from mid-September, sometimes until the end of November. As Didier Willery explains in Une année au jardin, “you need leaves to have roots, as the plant hormone that promotes rooting is synthesised in the leaves.” It is therefore in autumn that rooting happens the fastest.

⇒ This is the ideal moment to plant:

• Deciduous trees and shrubs not frost-prone
• Evergreen trees and shrubs not very frost-prone
• Evergreen plants in pots or bare roots (between mid-October and mid-April)
• fruit trees, the berries
• Conifers
• Hardy climbers
• perennials and grasses
• Biennials (digitalis, honesty, pansies…)
• Spring bulbs (tulips, daffodils, alliums…)
• Roses. The soil remains warm, promoting rooting before winter and ensuring a good revival in spring.
• ericaceous plants (azaleas, kalmias, rhododendrons…) and shade plants

→ Read also: What to plant in autumn?

In winter (between November and February), you can still plant shrubs with bare roots or in pots, and deciduous hardy shrubs (not frost-prone). Learn more in our advice sheet What to plant in winter?

How do soil, region and type of young plant influence the ideal planting period?

Never forget that every garden benefits from different weather and soil conditions depending on whether you live in Lyon, Saint-Jean-de-Luz, Lannion or Metz. Beyond these two fundamental components of the garden, plant type and its hardiness are also crucial in choosing the planting (or transplanting) season, as well as the plant’s cultivation method.

• Soil

  Soil is one of the most important criteria! If your soil drains well, that is, light and friable, or even dry, you have a wider planting window and can plant earlier in spring or later in autumn (August to November) to benefit from rainfall. However, heavy, clay soils retain moisture, which is detrimental to roots in winter, and are slower to warm up. For this soil type, mid‑spring is preferred.

• Region and its climate

  We usually divide France into three or four broad zones, mainly taking into account the timing and duration of frosts and below-freezing temperatures.
  – In montane regions, plant in spring 2 to 3 weeks later than the reference zone, which roughly corresponds to Zone 8 (see our article), and 3 weeks earlier in autumn
  – In coastal regions and along the Mediterranean fringe, you can plant 2 to 3 weeks earlier in spring, and up to 3 weeks later in autumn.

• Plant type

  It is important to consider the plant’s growth cycle when addressing the question of when to plant. The main difference lies between deciduous plants (which lose their leaves in winter), and the evergreen plants (trees and shrubs that keep their leaves year‑round). We favour autumn planting, or even late summer (between August and November) for the former, while the latter are generally planted in spring.
  Bulbs are planted about six months before flowering: the previous autumn for spring‑flowering bulbs, and in spring (March to May) for summer‑flowering bulbs. The later you plant, the more the flowering is slightly offset. Finally, annuals (petunias, marigolds, Nemesias…) are usually available quite late: that means you shouldn’t plant them before May.

• Plant hardiness

  Plant hardiness is also a key factor in timing the planting. For frost‑tender, but also slightly chilly plants that tolerate frosts poorly, it is important to plant in spring, usually between April and May, once frosts are no longer a risk. This applies to both deciduous and evergreen shrubs (for example palms, succulent plants such as cacti, Mediterranean‑type shrubs, exotic shrubs from South Africa, Latin America or Oceania such as Dicksonia, Protea, Podranea, etc.).

• Cultivation method

  Are you buying bare roots, a plant in a root ball, or a plant in its pot? Again, there are differences between plants grown in containers or pots for perennials, and those with bare roots. Bare‑root plants (even perennials) are theoretically sold only during their dormancy (November to March): they are planted in autumn, or at the very end of winter, which corresponds to their dormancy (these plants lose their leaves and enter vegetative rest), while plants growing in a root ball (root‑ball, intended for larger specimens) can be planted from the end of summer to the start of spring. Finally, shrubs, trees and climbers sold in containers are said to be plantable all year round… but as we’ve just seen, the wet months of the calendar are the best times to try planting them!

→ Read also Climate zones and USDA zones in France, Evergreen trees and shrubs, what is it?, Trees and shrubs: bare roots, root‑ball or in pots?

Type de conditionnement, région plus ou moins clémente, végétaux gélifs et type de sol : des éléments à prendre aussi en compte lors de vos plantations

Tips and recommendations

• Should we remind you? Never plant during frosts or during periods of extreme heat, drought or heatwaves
• The heel-in method allows you to keep shrubs or trees with bare roots (purchased or lifted) for a few days to 2–3 weeks, if the weather becomes less favourable during your delivery or purchase. More information on this technique at: When and how to heel in before planting?
• Bare-rooted trees and shrubs require a root priming to protect them and ensure a good establishment
• Watch the weather for the day of planting : it is always recommended to plant in overcast conditions, or at least without strong sun
• If you’re offered a shrub or a perennial in midsummer? Prefer re-potting into slightly larger pots and plant them in late summer or autumn. Unless your soil remains wet (but the plant must be suited to it)
• What about container planting on the terrace? In this case, you can practically plant container-grown plants year-round, always subject to good watering during the most critical months (often 2–3 times per week).
• Climate change can sometimes disrupt this ideal planting calendar. Warmer springs are increasing, but late frosts are arriving later as well, which can delay planting dates further. Conversely, in some regions, you may be able to plant even later in winter…

Learn more

At Promesse de fleurs, we aim to specify in each of our plant profiles the best planting period (in dark green on the calendar), and the reasonable planting period (in light green). This is to help you achieve the best possible results for your projects. Planting outside this calendar is far more variable for the growth and development of many plants. Of course, these data are averages, and as noted above you should also take into account your soil and your region, which can delay or advance these ideal planting dates somewhat.