There are couple of things you can try at this time of year while you wait for the blossom to really get going. One is medicinal, the other two are culinary.
This recipe for ointment I found on the web ages ago (my thanks to the originator whose name I forget now). It has a high reputation for effectiveness:
Elder ointment
This green elder ointment is also called "Oil of Swallows" because it's made in the spring time when the swallows return ...
It's made with vegetable oil as the base with a little glycerine added to soften it slightly and make it easier to use in cold weather. The active parts of it are elder leaves which are a powerful wound cleaner and helps irritation, comfrey which kick starts the healing system and lavender which is an antiseptic and makes it smell gorgeous! I haven't tried it for myself yet but apparently it can be used on many different ailments including eczema, cuts, sores, boils, burns, grazed knees and the invisible problems that children can see.
You'll need:
2 blocks of solid vegetable oil (e.g.. Pura)
1 small bottle glycerine
Approx. half a carrier bag of freshly gathered leaves made up of 3 parts elder leaves (no woody bits) to 1 part comfrey leaves
2 handfuls of dried lavender flowers or lavender essential oil
Gently melt the blocks of vegetable oil in a large pan and add a small handful of the leaves. Slowly let the leaves infuse the oil which will gradually turn green over the course of making the ointment. When the leaves look like overcooked spinach, remove them and save in a muslin bag sitting in a bowl. Add another handful of leaves and repeat until all the leaves have been used and the oil is pale green.
Either add the lavender flowers and continue to heat the oil gently for a further five minutes or stir in enough lavender essential oil to pleasantly scent it and turn the heat off.
When the used leaves in the muslin are cool enough to handle, squeeze any remaining oil and juice from them into the main pan and stir to disperse.
As the oil cools, it will gradually start to change colour. Whilst it's still pourable add half to one bottle of glycerine and stir periodically as it cools as the glycerine tends to settle to the bottom of the pan. Carefully pour into small jars and allow to cool.
The one that Minamoo's mentioned is my own version of an old recipe :
Elder bud pickle - Collect enough elder buds to fill a small le parfait or kilner jar. Snip them off their stems down to small 'florets' and wash thoroughly. Put into a saucepan with 1 tp Mace, 1 tsp peppercorns, 1 tsp seasalt and the pared and shredded rind of a lemon try to avoid the bitter pith. Top up with the vinegar of your choice (which you will have already measured off into the jar you're using to have roughly the right amount), white wine or cider, or even malt vinegar if you like the taste (personally I find it's bit strong and raw for me).
Bring to a swift boil, and take immediately from the heat. Strain off the liquid and allow it and the buds to cool separately (doing this stops the liquid from overcooking the buds). Put the buds into your sterilized jar (don't use one with a metal lid - Le Parfait or Kilner with a rubber seal is best). Pour over the vinegar liquid - add or remove any of the spices as you prefer, and seal securely. Leave for a month or so to mature and develop the flavour.
This is a bit like pickled capers or nasturtium seeds, and would prob go equally well with fishy dishes, but I like it as salad pickle variant in a ploughmans. If the buds aren't overcooked, they should still have a crunchy texture. I don't tend make this in large amounts because I'm the only picklehead in our house. My version of the recipe has been tweaked with the addition of garlic and chilli - possibly not to everyones taste - but you can be bold and experiment!
Elder flower pickle - (haven't got round to trying this one yet - if you anyone does, could they report back please!?)
Gather enough flowerheads to fill a smallish jar (as above). Shake them lightly to remove unwanted guests, give them a light rinse, and snip down to smallish florets. Fill your jar. Boil some white wine or cider vinegar and pour over the flowers in the jar. Pop the lid on loosely and leave for an hour to cool, then strain off the vinegar and use the florets in a tossed salad. Keep the vinegar for another occasion