I'm assuming you are talking about syringa vulgaris. Perhaps it isn't getting enough sun. They will do much better in a full sun situation. In fact, they require it. Lilacs also require cold winters to do well. Are you in a nice, frosty area?

Lilacs begin to produce their flowering bits in autumn (although the actual buds don't emerge until spring). If you prune during winter, you actually remove the bud material. If you need to prune, do if after flowering - or when flowering would have occurred.

I wouldn't give up - the perfume is worth any amount of TLC. Perhaps you could move it to a position where it would be in full sun for most of the day. Lilacs like a rich, alkaline soil so give the site a good dressing of lime and incorporate a lavish application of organic material.

Lilacs like moist soil, but not wet feet. Your new spot should be well drained but keep up the water over the warmer months. Mulch to conserve moisture, keep the soil cool and cut down on competing weeds. Once the shrub is established, fertilise regularly.

The heavy pruning you gave it last year and a move to another site could set back flowering for another year or two. But don't be completely disheartened. Keep remembering the promise of the beautiful perfume.

If you don't live in a cold winter area, there are a number of lilac species which flower at various times of the year and some of these will take warmer conditions.

Thanks for that. It may not be cold enough although it's cold enough for me (Melbourne). rarely get a frost and it may be the lilac is in too much regular shade for its liking. Because it's in amongst natives I don't lime the area but it's well mulched, well drained and reasonably well watered (for a native garden). I may have to consider another move if I want that wonderful perfume.

Sunlight levels can change over the years without our noticing. Check overhead trees, nearby trees, etc... Light level is most probable problem and can be easy to assess.

Mak1 is quite right about the light levels changing - trees grow, etc.

However, you may not want to remove branches or cut back your Australian natives. And you might have to remove a lot to give the lilac its daily minimum 6 hours of direct sun.

Much easier to move the lilac to an open position. This will also enable you to give the lilac its soil conditions, fertiliser and water requirements without adversely affecting your natives.

I used to live in the inner-city area of Sydney where the nearest thing we got to frost was the David variety on television (hand me my walking stick, dear). I just had to have a lilac so I got myself a Madame Lemoine. It grew beautifully. Flowering was a bit of a problem - not many trusses and they were quite small. But, hell, you only need one for the perfume. And I always got at least one.

Now I have huge old bushes, a climate they are happy in, and masses of flowers. And I molly-coddle plants like Yesterday, Today & Tomorrow which shouldn't grow in my climate. We all need a challenge :-)

Many thanks for that advice. Do you think it (or another one) would grow in a big pot? I'd have to remove other plants to find it a garden spot in full sun (I'm convinced that's the problem,there's a big peppercorn shading it till at least mid afternoon. I could get a big heavy pot and put that in a south facing but very open position next to a potted cumquat which might be nice near the front entrance. Am I dreaming?

I wouldn't regard it as dreaming .. I've been trying to get a frangipanni to survive over winter without the benefit of a glass house. Tried wrapping one in bubble wrap over winter (should have let the pot dry out first I think - it rotted at soil level). Have looked up various information on the net and, in the process, discovered a gardener in Ireland with a frangipanni growing indoors - 10 feet high!! And it flowers. I'm waiting for one of the kids to move out permanently so I can take over a bedroom.

Back to the challenge ... No harm in trying a large pot. Lilacs produce a fairly thick, dense mat of roots near the soil surface which, in a pot, is going to affect the penetration and holding capacity of water. After a couple of years, you might have to remove some of the root mass and replace with compost. If the pot is a BIG one, you might be able to cut out a few chunks of root mass with a long serrated knife (like a bread knife). I wouldn't attack the whole root area in one go - stagger the removal of chunks.

Hello guys,i know your posts are from few years ago but was hoping someone will help me or give me an advice about my lilac tree,syringa vulgaris. We had it for few years now,the flowers are tiny and the leaves are always going brown:( what am i doing wrong??Forgot to mention that we live in Perth,WA

Please help,thank you

Maya

also i've included some photos