We are planning a visit to Scotland in 2019 and want to see the Heather in bloom. We do NOT want to go during the peak Summer time and are hoping it will still be in bloom when the schools restart in September......possibly looking at mid to late September. Will we be too late to see it then?
thanks in advance for any advice.

Most heather blooms twice. In early summer and in late summer -- exact dates can't be pinned down. It is very weather dependent. If it was a late or really wet Spring the bloom season will be later. If it is a dry/warm summer the bloom will be over by Sept. Sometimes it is still lovely in Sept and sometimes it isn't.

If it was me I'd travel in June before the schools let out, then the heather, broom and gorse would all have a better chance for bloom. (Most British/European schools don't let out until around mid July)

It also has to do with altitude, orientation (north v. south) and the soils. But really, heather is everywhere, and you'll see decent flowers pretty much any time between June and the early autumn. Even though September is often past the peak, I still like the contrast between the heather and early autumn color - bracken, trees, etc. - that you can get in September, even October sometimes.

And of course even in the peak summer tourist period, it's very easy to get away from other people and go pick wild mountain thyme, all around the bloomin' heather, will ye go... oh wait.

For example, one of my all time favorite drives is through the lovely village of Gifford in East Lothian and up into the Lammermuir Hills - barely an hour from Edinburgh you can get views like this - https://goo.gl/maps/bTuZX3pXQEU2 . Just you and the sheep.

Here's a terrific day's outing from Edinburgh that includes Rosslyn Chapel, if you're on a Grail Quest. - https://goo.gl/maps/c1Sf1sj3tpq . It includes Gifford, the Lammermuirs (get a copy of a CD of Lucia di Lammermoor for the car if you like that sort of thing,) and Etal, a tiny village just over the English border that has a nice wee ruined castle and the most northerly thatched pub (and a good one) in England. Even in peak summer, you're not going to feel even slightly crowded.

Mid to late September could be a bit late to see the heather at its best. August is the best time, although early September should still quite a lot of heather in bloom.

Don't forget Scottish schools break up and go back earlier than English school. Most start back mid August. The Scottish August Bank holiday is at the start of August, unlike the English one which is the last weekend in August.

We are just back from Scotland and saw heather in bloom on Skye. We were on Skye the first week of September.

Re my comment up thread: September is an truly wonderful time to visit Scotland. Just not if your heart is absolutely set on seeing heather in full bloom. If that is one of your main reasons for visiting - then you can't count on it. I've been in Sept when the hills were purple, and other Septembers when it was well past.

Many thanks to all. Still thinking and planning. Maybe not next year as the timing was to see the Heather in bloom. Not our first visit to Scotland but wanting to dodge the crowds ( and midges ) in Summer.
Cheers