Lavender in trough planters

Hi, we have some lavender plants and have decided to plant them in some wooden trough planters placed in our front garden will they will get lots of sun light.

My question is do we need to line the planter with some kind of membrane and also what soil is best to fill the planters with?

I’m a complete beginner when it comes to gardening so please keep any advice very simple to understand for a novice like me.

Thank you all.

David

 

Not a plant I grow, as I don't like it, but yes - it's always better to line a wooden planter. You can use old compost bags if you have them- just staple them on. Membrane isn't any good as it lets water through, so you wouldn't be protecting the timber.
A soil based mix is best for any plant that's going to be potted long term. Compost is fine for a season, but it gradually disappears, so it's not ideal for long term use. You can buy soil/loam based mixes at GCs etc, or you can mix some garden soil with any compost you already have. Some grit mixed in as well will help with keeping the drainage right, as lavender doesn't like being waterlogged.
It's also a good idea to fill the planters really well. Any soil mix will gradually drop over time, and that can be a pest as the plants will then be too low. You can add a layer of grit or gravel around the plants once they're in. That's mainly for aesthetic reasons.
If the planters are going on a hard surface, it's also a good idea to raise them up a little and that will allow excess moisture to get away, especially in winter. Anything will do - I often use little offcuts from timber battens or similar.

Although it likes sun and good drainage, it doesn't mean you won't need to water well, especially through summer, and especially if you're in a generally dry area. An evergreen plant can also prevent rain from getting in well once it's grown larger. Anything in a container relies on you for it's needs. Hope that's of some use

 

Lavender prefer impoverished soil so don't be tempted to add any feed or manure. On the recommendation of another forum member I also added some gravel (not grit) to my compost mix, using John Innes No 2 soil based compost and multi purpose compost in ratios of about a third for each. It's not an exact science but good drainage and low nutrient levels are important for success with Lavender, as well as a sunny location!

 

I recently made up some plastic troughs of lavender and i used Multi-p compost and plenty of grit, maybe 25% of volume in total. It was only last weekend so can't really comment on if they're happy or not. I'm potentially planning to plant them in the ground maybe next year when they're bigger to line our driveway so growing them up in troughs first.

 

Thank you all for your responses, that’s really helpful.

man I right in thinking if I add a liner to the wooden troughs to stop the water damaging the wood then I would need to add some holes in the bottom of the lining to allow water to drain. Seems a really obvious point but I’m a real beginner so this is all very new to me.

I will take the advice and add some grit or gravel to my mix.
I was advised to use miracle-gro peat free ericaceous compost so I was planning on using that but assume it’s ok to add some grit or gravel into that?

The planters are going to be sat on top of small decorative stones so I don’t think I’ll need to raise them up at all as that should act as good drainage.

 

Yes - holes in the base through the liner.
I'm not sure who's advising you to use that compost. It isn't sufficient long term - fine for the summer season, but that's all. Most lavender isn't keen on acidic soil either, so an ericaceous compost won't be ideal.
Some composts are heavier than others and retain moisture too well, and some are the total opposite. That's why a soil based medium with grit mixed in is the way to go, and a bit of compost for a few nutrients - all commercial composts tend to have additional food mixed through them.

The gravel should help to keep the drainage good. Most of my containers sit on gravel, and even with the amounto frain we get here, it's more than adequate.

 

Thank you all for your responses, is there a particular gravel that everyone recommends to mix in and would you say about a 3rd of the overall mix is about right for gravel quantity?

 

I bought gravel from my garden centre @DavidMey. If there is more than one size of gravel, choose the smaller size. A third of gravel in the mix will be fine. Good luck with your planting!

Just thought I'd also add that although they like free drainage, Lavender plants in containers do need watering. They become more drought tolerant once they get established.

 

Lavender doesn't need ericaceous compost - that's only needed for acid-loving plants like rhododendrons etc. Lavender apparently prefers a slightly alkaline soil but I don't think it's fussy about it - it grows well enough here on slightly acid. As others have said, the main thing is good drainage - they like the gritty sandy sandy soil here.

You want a grit to mix into the compost rather than a gravel that you'd use for a path (although they won't mind some bigger pieces). This sort of thing rather than this. I'm not suggesting Wickes, it's just what Google came up with that had decent pictures. Links with pictures for avoidance of confusion - what I call grit, others might call fine gravel. I've come across someone (on another forum) who used the term grit for what I would call coarse sharp sand. Terminology can be confusing!

 

Nothing bigger than about 10mm is fine. Ordinary pea gravel is fine, if you don't want to spend more money on horticultural grit which is finer.
Watering is vital. Pots are not the same as a plant in the ground.

 

I've noticed that when I've bought "10mm" pea gravel, quite a lot of it has been bigger than that, but it probably varies a bit between suppliers. Best advice is probably to have a look at it before parting with your dosh.
These days horticultural grit seems to be £6 for 20kg which I don't think is a bad price. It works out more expensive per kg if you buy smaller bags, or get it from an online supplier that factors in delivery.