Starting New Guinea Impatiens from Seed

[John Blair 7]

Hello - I'm brand new to the forum and this is my first post. I'm hoping the kind folks here can help me with my question. 

 

I have a very shady yard and have enjoyed the beauty that impatiens have given me for the past 25 years. Last year, I was shocked as Downy Mildew ravaged all 20 flats of my planted impatiens. I have read Janet's article about Downy Mildew and do not plan on trying to replant impatiens again next spring as I believe the spores are now present in my soil and I would again lose my impatiens. However, I have read that New Guinea impatiens are Downy Mildew resistant. I have purchased about a dozen of these every year for my deck pots and they grow beautifully and were indeed untouched by the Downy Mildew - even when infected regular impatiens in the same pot succumbed. Not wanting to forever lose my beautiful impatiens, I have decided to grow my own New Guinea under lights in the basement (as opposed to purchasing them - at $3.50/pot, it would be far too expensive for the large number I need). Here is where I need advice. How do I best grow these plants from seed (special lighting/heated seed mats, etc)? I have seached the internet, but have not been able to locate instructions suitable for a home gardener like me to do this. Any advice will be greatly appreciated :-)  

[Margaret Thele 16]

Having never grown the New Guineas specifically from seeds, but having grown lots of seeds - I can give you one good tip. LIGHT. It helps to have a lighting set up so you can put the light about 4" from the developing plants. As for seed heat mats, I would say unless your basement is particularly cold, I would probably not recommend it unless you have that cold problem. The New Guineas - with out researching on the net - probably want to germinate around 70F - so that is your target temp. You can probably find some good growing info on the net. Lots of growers grow from seed. Many of the New Guineas are probably started from cuttings as well.

[Margaret Thele 16]

http://home.howstuffworks.com/new-guinea-impatiens.htm  - not very detailed instructions - but basic info - indicates that only two varieties of New Guineas can be grown from seed.

[John Blair 7]

Margaret, Thank you for your response and the informative link. Regarding light, in the past I when I have grown plants from seed (usually vegetables), I have used an array of four shop lights with 40 watt flourescent bulbs over my seed flats and I have used the typical white flourescent bulbs (although I think I added one Aquarium/Plant flourescent). Are these the type of lights and bulbs you would recommend or are there more specialized lighting I should be using for my New Guinea seeds? In case it is helpful, the New Guinea seeds I have ordered are the ones in the new Jung seed catalog listed as "Divine Hybrid New Guinea impatiens" - both Mystic mix and Hot mix. Also, per your suggestion,  I will check the temp in the basement because I may not need the expensive seed matts after all. Thank you for your guidance!

[carolm 1]

Probably just as important as light and temperature is timing.  Start your seeds too early and you'll be dealing with mature plants weeks before they're able to be planted outside.  You might be faced with the prospect of having to transplant them to larger pots, (which will take up much more space), or keeping them in the original containers and hope they don't get too stressed before the warm weather comes. 

[Margaret Thele 16]

Having used lights in the past - I used a mix of cool white and warm white fluorescents...There are also the more expensive T5 and T8 bulbs that mimic full-spectrum sunlight that can be found at http://www.GrowersSupply.com.

[John Blair 7]

Thank you, Margaret - this is the info I was looking for! On another note, last fall I was pleased to see a new gardening store called "Hydroponics" open up in one of our local strip malls. Figured I would stop by yesterday to see if they had any lighting better than my current shop light setup I could use to start my New Guinea impatiens. As soon as I walked in, I realized that the equipment they had looked unlike *anything* I had ever seen in a garden catalog and when I asked the gentleman about recommendations on my impatiens, he informed me that this equipment was not typically used for starting flower garden plants. At that point, I realized this equipment was all for growing Marijuana. Ooops. Strange times we live in.

[Joananne 0]

I am new to this forum and have been growing annuals, vegetables and perennial seeds for many years. I invested in wire shelving racks and double 2 bulb fixtures over each shelf. The question I found not covered is the bottom heat issue. To germinate at a warm temperature I use regular heating pads...so much less expensive than heat mats. On low temp setting I can regulate the temp by using layers of toweling. Seeds that require warmth to germinate pop up in much shorter times than listed on seed packages. This will be my first attempt at starting new guinea impatiens..Divine series.

[donna saverino 0]

I know this is a few years later but I'm doing just this.  Found everything much cheaper for the T8 light and 6500 Ks bulbs at Lowe's.