A light, slow release fertilizer matched to each species and applied in spring is the best choice for both trees, and a Douglas fir growing in a natural setting often needs no feeding at all. Where the two trees differ is the soil around their roots: Douglas fir needs it well drained, while hemlock needs it moist without being soggy.

Why do these conifers need only light feeding?

Evergreens like Douglas fir and hemlock hold their needles year round, so they need nutrients that support foliage and root development rather than a push of fast growth. Excess nitrogen produces weak growth, and bark beetles such as the Douglas fir beetle go after trees that are stressed or weakened.

What soil does each tree need before it's fed?

Douglas fir adapts to loamy, sandy, or clay soil as long as it drains well, since wet or waterlogged ground invites root rot. Hemlock prefers soil that is nutrient rich, slightly acidic to neutral, and moist but well drained, and it tolerates neither very wet nor very dry conditions.

How is the fertilizer applied?

Each spring, TreeHelp Premium Fertilizer: Douglas fir goes down around a fir and TreeHelp Premium Fertilizer: Hemlock around a hemlock, both placed below the grass roots near the drip line, the circle beneath the outer edge of the canopy. Their slow release nitrogen then feeds the roots through the growing season.

Frequently Asked Questions

Can fertilizer protect a hemlock from woolly adelgid?

No. To protect a hemlock from this invasive insect, which infests and eventually kills trees, Once A Year Insecticidal Drench w/Merit is mixed and poured at the base for 12 months of protection against adelgids.

Can fertilizer fix browning, shedding needles on a Douglas fir?

Not always. Needle cast diseases, caused by various fungi, discolor needles and make them drop early, so the problem is fungal rather than nutritional.

Do young Douglas firs and hemlocks need extra water?

Yes, during dry spells. Young Douglas firs benefit from regular watering, and hemlocks cope poorly with very dry soil.

Can one bag feed several young trees?

Yes. One 3.3 lb bag of either fertilizer covers two to three smaller or newly planted trees, or one mature tree.