Getting it to bloom

Why won't my Engelmann Spruce bloom? (and how to make it flower)

Also called Engelmann Spruce, Mountain Spruce, White Spruce (Picea engelmannii).

More about engelmann spruce

About Engelmann Spruce

Picea engelmannii · also called Engelmann Spruce, Mountain Spruce · flowering

Engelmann Spruce is a high-altitude Rocky Mountain conifer, one of the most cold-hardy trees in North America. It dominates subalpine forests from British Columbia to New Mexico, forming dense stands near treeline. Blue-green to silvery needles and a narrow spire shape make it ornamentally valuable in large cold-climate gardens with moist, acidic, well-drained soils.

Plant type: flowering

Watch for — Spruce Budworm: Choristoneura occidentalis defoliates new growth in outbreak years, causing repeated dieback. Young trees can be killed within a few years. Btk (Bacillus thuringiensis var. kurstaki) applications at larval emergence in spring protect new growth without harming beneficial insects.

The reasons engelmann spruce isn't blooming

Almost every non-blooming engelmann spruce traces back to one of these, roughly in order of how common they are:

Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
The plant has not been deadheaded, so it stops flowering once it sets seed.
Irregular watering — drought or waterlogging at the budding stage makes buds abort.
It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding engelmann spruce a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get engelmann spruce to flower

Maximise sun. Give engelmann spruce the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for engelmann spruce and get the feeding right with the engelmann spruce fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Engelmann Spruce flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full engelmann spruce care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Engelmann Spruce blooming — frequently asked questions

Why won't my engelmann spruce flower?

Engelmann Spruce blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make engelmann spruce bloom?

Give engelmann spruce the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does engelmann spruce normally bloom?