Species selection and soil amendments for coastal tree planting

In situations like that I always ask nature what works? I look at what has worked in other places just like what you are dealing with. If there is nothing that works in nature in your location I would plant what is most likely to work. I am guessing that shrubs might be your answer, can you think of any first succession(pioneer) shrubs that you could plant and tolerates salt. These are the weeds that you would see along the beach. Around here I have some ideas but I grew up on an inland freshwater great lake in zone 3 and that would not be the best choice for your situation.

Nyssa sylvatica (black tupelo) is a wonderful tree that does well in sandy coastal soils. I also second the shrubs cited by Mr Garulay…both myrica and comptonia fix nitrogen too! Bonus
I would use caution with the rugosa rose…I believe they made the list of invasives in the northeast a couple years ago.
Best of luck

Cape Cod Cooperative Extension has a nice list of plants appropriate for fresh water buffer zones and coastal buffer zones. This one is now used as the standard for most local town conservation commissions. It has recommended plant size and spacing as well.

http://www.capecodextension.org/docs/horticulture/fact%20sheets/trees%20&%20shrubs/growing/sec_buffer_zone_plants.pdf

Geoffrey, you should also keep in mind that the smaller sized plants tend to have a higher survival rate in sandy soils. Sometimes the commissions think you are trying to save money by going small, but it really makes a difference in helping them establish before they have to much dessication from too much foliage. Beach plum is a great example. They grow in sand, but you can’t plant a big one or it dies.

Eastern Red Cedar (Juniperus virginiana) is also very good in a near dune situation up here as well. Probably the best bet for a tree in this type of environment in my area.

Find the oldest photographs you can of this and close/similar areas from archives and see what grew then.  Check for what local tribes picked/ate/used.  Consider replacing areas of dead sand, ie not yet converted to soil but not likely to have sand added now and consider upgrading them.  Spent mushroom compost mixed with a top layer of fresh soil is good.  Protect with a berm planted with grass, a ribbon of salt tolerant bushes and pioneer species followed by what you want in the harder soil area.  Check that these defences and area generally will have a protected status (“nature centre” or not).  My mind keeps telling me of the trees planted in grass to halt desertification in Kenya only to be burnt as fuel by the locals.  Where this project is being realised I bet locals have wood burning stoves, lol. 

What did grow should grow again but, especially, if you can grow trees from local seed.  Local stock will be best (so establish a nursery from the start to plant out what you have grown approximately free), always but, allowing for climate change, include what might only self seed now 50 miles down the coast. or 100.  If you use pines as suggested – and it might be nice to have ground hugging juniper and so on – have the water drain to sea or face acidification of the soil.  There is nothing wrong with formal gardens and this is where resorts win out.  If the area is supposed to look wild, there is still nothing wrong with, for example, whole swathes of heathers in ericacious soil or lavenders and mediterannean plants like rosemary and pinks/carnations/dianthus under lavateria cover.  Whatever, your planting schedule should allow for improving soils and what will grow there in time, not to mention increasing the area as dunes grow and more land becomes available.  Lavateria, for example, needs gardening to last maybe 15 years and as, presumably, you do not want a mangrove swamp or something going mad to exclude other planting, you have to plan and budget for this.  Who will do the work and pay for it?  Many nature parks have an army of volunteers, long-term unemployed, etc. 

Stormwater management is often a misnomer.  What people really mean is we have all block paved our front yards to accommodate extra cars and chopped the trees down upstream so let’s have a fake wetland and more trees to act as a sponge and prevent short term flooding.  The real job is to work with what you have and what you are going to get, not fit in the number of living units a client wants and cope otherwise.  Else we would all live in small homes next to the aforesaid mangrove swamp and have to pay to have a malaria control unit every few miles.   Honestly, this disease is a real worry again especially in wetland areas in our lattitudes as is blue tongue disease in cattle and other things.  The reality, of course, is that we must compromise and come through as the bright crew member who is otherwise so expendable in a Star Trek episode, winning through on behalf of humanity while others enjoy the benefits in lotus-eating

ignorance. 

I do not know your flora and fauna and, save for the tips given, recommend finding some amateurs who do.  They may have records going back 200 years and I think of the many wildlife, lepidoptera and other groups around, not just the university professor though there could be overlaps.  Similarly, there should be another group further down the coast to compare changes since the end of the mini ice age and archeological departments of local authorities may also assist.  Only with this research can you speak from a point of authority as to what you can re-establish wild, grow as a useful ornamental, introduce to the wild or use for specific purposes, eg sphagnum moss in a bog establishing a mini industry of filling hanging baskets or selling the dried moss.  Certainly, you can plan for folk using what they can get to make money as surely as planting cork oaks to support a local bottling plant – to give a way-out example.  All of this may be wasted, of course, if the clients have already settled on an information centre, toilets, car park and petting zoo for farm animals earning a crust from education authorities anxious to show kids where an egg comes from, etc. or an overflow pond in a further floodable depression with stormwater pipes leading through it.  There no-one will care what it is greened with between floods and a bird hide may be all the facilities allowed for.  Sorry, but it all happens so very often as those in charge realise they need to do something to show willing but, in fact, rising water levels do not promise that expenditure on real sea defences is worthwhile or affordable.  Wetlands are, in effect, the new acquiescence to global warming even next door to nuclear facilities.           

It definitely makes sense to get in tune with what is naturally occuring in the environments that the project is in. I still think you need to, as an LA, formulate a pallet to use in order to design a landscape that is designed to its intended use. The purpose is not to restore a natural environment, but to make the built environment more closely support the natural environment that it exists within. Form should still follow function and obviously parts of the project may function as natural restoration while others may not.