What type of shade trees would be suitable to plant beside the ocean?

Question:

Recent storms have severely damaged two spruce at our camp. We are at ocean’s edge on granite. The soil is two feet at best in depth. The site increasingly is hit with salt water several times a year. Spruce bud worm has infected the trees that are presently there. Can you recommend another species of tree that could provide shade?

Answer:

Jonathan Foster, Home Horticulture Outreach Professional

I recommend the Cumberland County Soil and Water Conservation District’s Coastal Planting Guide for the best, targeted information on what you have in mind. While their focus is on shoreline stabilization, it offers a nice selection of salt-tolerant plants. You will see that the two groups of trees discussed are both labeled as deep soil, but some trees (like your spruces) are more tolerant of shallow soil. I’m somewhat cross-referencing these trees with the UMaine Cooperative Extension’s Salt Tolerance List.

For deciduous trees, I’m liking either the Cockspur Hawthorn (Crataegus crus-galli) or the Yellow Birch (Betula alleghaniensis). Both are fine in wettish conditions, will tolerate moderate to high salinity, should be fine in shallower soil, and will provide nice shade. We’ll stay clear of oaks because of the soil depth. For evergreens, you could consider Northern white-cedar (Thuja occidentalis), which will be fine for the salt and wet conditions, but can develop needle burn if it’s too windy (which it may be on a seaside property, depending on your orientation). Also, if your shade needs are flexible–i.e., shading a patio or garden space, as opposed to the whole yard and house–you might have good luck with the larger shrubs listed.

A few other resources you might check:

1) Plants for Seaside Gardens (another good list of salt-tolerant species)

2) UMaine Cooperative Extension Bulletin #2500, Gardening to Conserve Maine’s Natural Landscape (which focuses more broadly on natives, but also gives a bit more information about several plants on the first list).
3) The State of Maine’s Buffer Plant List, which is just a great resource for all kinds of questions like this.

Best of luck and happy gardening.