Why Does My Lavender Have Very Few Flowers?

When lavender produces only a handful of sparse, short flower spikes instead of the generous purple display you were expecting, it is worth comparing what the plant has against what it actually needs. A reduced flower count rarely happens for a single dramatic reason — it is more often a combination of suboptimal conditions, each taking the edge off flowering potential. Understanding which factors are at play gives you the best chance of a markedly better display the following season.

Partial shade throughout the day

A lavender receiving five hours of sun rather than eight will flower, but sparsely. The plants are photosynthesis-driven flowering machines, and reduced light hours translate almost directly into reduced flower production. Check whether shade from a neighbouring plant, wall or structure has increased since the lavender was planted. Even trimming back an overhanging branch can make a measurable difference within the same season.

Overly fertile or recently amended soil

Lavender that has been fed with a balanced or high-nitrogen fertiliser will respond by producing vigorous leafy growth at the expense of flowers. Similarly, if the planting area received a fresh top-dressing of compost or manure, the lavender may simply be too well nourished to bother with the reproductive effort of flowering. Stop all feeding and allow the soil to rebalance over winter; add grit around the plant to improve drainage and counteract the richness.

Woody, ungrown plant lacking fresh shoot tips

Flower spikes are borne on the green shoot tips produced the current or previous season. An older, woody plant with few fresh shoots will simply not have the available shoot tips from which to produce flowers. A light renovation prune in early spring — cutting back into the lower green growth without going into bare wood — triggers a flush of new shoots that carry this year's flowers.

Wrong variety for your climate

English lavenders (Lavandula angustifolia) are hardier and often flower better in cooler northern climates. French and Spanish lavenders (Lavandula stoechas and L. dentata) prefer warm Mediterranean conditions and flower poorly where summers are cool and damp. If you are in a cooler region, swapping to an angustifolia variety such as Hidcote or Munstead will typically give a much better display.

Deadheading too late in the season

Lavender can produce a second flush of flowers on some varieties if the first flush is deadheaded promptly. If you leave spent flower stalks on the plant until late summer, you effectively remove the opportunity for a second display. Cut off the spent stalks to just above the first leaves as soon as the flowers fade, and water the plant once if conditions are dry to encourage the second growth push.