HomeBlueberriesBlueberries: Flowers turn brown

Blueberries: Flowers turn brown

Flowers may turn brown after pollination by a natural process:

When flowers turn brown before pollination, likely causes are:

Flowers may turn brown at any time during their development due to

Sudden and complete browning of blossoms and leaves indicates a virus, either

Post pollination browning

Post pollination browning occurs once flowers are pollinated. Corollas may turn purple, then brown, but this is normal. The concern is when the flower parts rot before pollination occurs.

Unripe cluster of blueberries. Fruit are green and some have brown flower remnants attached to crown.

Botrytis blossom blight

Botrytis blossom blight causes blossoms turn brown then become covered with masses of powdery gray spores. These spores are carried by wind and rain to developing fruit, causing Botrytis fruit rot.

Cluster of blueberry flowers with tan-orange wilted blossoms and shriveled deep blue flower bases.

Blooming blueberry bush viewed from above. Small clusters of blossoms have shirveled gray-blue stems and tan petals, instead of plump, white, healthy petals on green stems.
Botrytis blossom blight can attack disparate blossom clusters on a blueberry bush. Photo courtesy of Laura McDermott.
Close-up of blueberry flower cluster. Flowers are wilted with tan-brown petals and blue-gray calyx with pink calyx edges. Small white spores on white stalks are emerging from petals.
Botrytis sporulating on blueberry flowers. Photo courtesy of Heather Faubert, URI Expension.

Anthracnose blossom blight

Anthracnose blossom blight causes blossoms to brown then become covered with salmon pink ooze.

Wilted cluster of blueberry flowers. Stem leading to flowers is initially green but has sudden brown section that extends to blooms. Flowers look wet and wilted. Blossoms are orange-beige and flower bases are grayish-pinkish.

Frost damage

Frost during bloom may cause serious damage to developing flower buds and blooms. Once flower buds open, coldhardiness for the most part is lost. Temperatures of 28 F or lower may result in frost damage.

Cluster of blueberry blossoms. White blossoms have tan-orange tint, especially on most exposed blossoms. Flowers look wilted.

Blueberry blossom cluster with brown, dry-looking petals.

Two small, flat, green blueberry fruits with stem cap attached, viewed from the blossom end. Flower on right is opaque and green, fruit is same color as stem cap. Fruit on right is semi-translucent, dark, and appears water-soaked. The stem cap is waxy and pale, similar to the healthy fruit.
Blueberry fruit in early stages of development. Fruit on left is healthy. Fruit on right has frost damage.

Blueberry Shock and Blueberry Scorch viruses

Both Blueberry Shock and Blueberry Scorch viruses may cause sudden and complete browning of both blossoms and leaves. Blueberry Scorch infected plants may appear to recover as a second flush of new leaves often occurs sometime later in the season.

Blueberry plant with red, wilted leaves all the way down the branches. Half of the leaves are dead, and half appear healthy and green.
Blueberry shock virus.

(Photo courtesy A. Schilder, MSU)