Getting your Japanese Indigo Seeds Started


With Spring Equinox now past, and the days getting longer and longer, it's time to start thinking of getting your dye garden going.

So many of you have bought seeds from me this year, and by far the most popular is the persicaria tinctoria, or Japanese Indigo.    And depending on where you live, it's time to get your seedlings going.

The first thing I will say is that Japanese Indigo is very forgiving, and very easy to grow.  I'm going to give you a few tips here, but if you are not a seasoned gardener, I hope these don't overwhelm you.  You don't have to follow each one of them.  And if you are a seasoned gardener, then just do whatever has worked well for you in the past with other plants - the indigo will follow your lead. 

Japanese Indigo seeds should be started indoors, ideally around 6-8 weeks before the last frost.  I live in Toronto, so our last frost is quite late, generally around mid to late May.  I'm not too fussy about calculating the exact number of weeks, I'll just get my seeds started sometime in the next week or two, the next time there is a nice sunny day that makes it pleasant to work outside (even though I'll be keeping them indoors at first, it's so much nicer to do the actual dirt wrangling outside).

And if you are lucky enough to live somewhere that the frost date is already much sooner than 6-8 weeks from now, don't stress - again, they are very forgiving, and you are able to several harvests out of one crop anyways.  So ultimately, just plant them when you can!

I have used all sorts of different types of seedling trays over the years, such as the peat ones in the top photo, or recycled black ones that I kept from previous years.  But if you don't already have some kicking around - don't go out and buy any!  You can easily make your own out of household materials.  One year I used this tutorial to make pots out of newspaper, and it worked great!  

And Japanese Indigo guru John Marshall doesn't even bother to separate his seedlings into little pots - he just scatters seeds onto big flats of soil, which is what I am going to try this year.

So choose whichever option works for you, but you'll generally be aiming to plant 5 or so seeds per square inch, and want to cover them with around 1/4 inch of soil.  Many people recommend soaking your seeds overnight before planting, but that is actually advice that pertains to the classic indigofera tinctoria, which is a harder plant to grow, and I never bother to soak my seeds.

You can use any type of potting soil - again, these plants are not fussy!  When it is time to transplant your seedlings, you may want to add some compost or manure, though this is not essential.  Nitrogen rich soil helps in the production of hearty leaves, which is where all the colour is.  So if you only add one thing to your plants, I would recommend a spray-on fish emulsion, which you can add to the soil periodically once the plants are established in your garden or in pots.  But I will warn you that it stinks!
Keep your seedling trays in a sunny window, and keep well watered.  The plant is native to the Tokushima region of Japan, and grows there during the monsoon season, so they prefer to be kept warm and moist.

And that is really it!  Did I mention that these plants are easy to grow?  Originally, these plants are weeds, so don't overthink it or stress about your plants, especially if you are new to it.  Take your seeds, add some dirt and water, then give them some sunshine and more water, and I'll be back in a month or so to talk about up-potting and then transplanting your plants.

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