where are you???

outdoors????

what are ambient temps????

green algae means too much water.. or the wrong media ...

you really havent given us many facts to speculate about ...

ken

I'm starting in my heated shop....... Ambient temp .... Google it....... ProMix aint the wrong stuff...... They're only watered when they need to be watered...... What other info do ya need?

Now back to my question.......... Should my petunias be bigger than they are after 2+ weeks of germination?

They can be slow to get started but should pick up speed soon. I have certainly noticed that some types grow faster than others.

The larger ones here were sowed a month earlier than yours - Jan 19th

This post was edited by mandolls on Tue, Mar 12, 13 at 14:43

Thanks mandolls for your insightful post! I'm wanting to move my Pets to my newly built GH, but I thought I should wait until they got a little bigger & our crazy Kansas weather calms down. I'm heating my GH, but it still gets down to the low 40s at night........ One more cold night here, then we're supposed to climb into the upper 60s with lows in the 30s......

What, if any, fertilizer are you using on yours?.

Your Petunias look great. It is my first season sowing them as well and they were really slow at first too. Not sure if it was coincidence but mine took off after I fertilized the first time. I used a 10-52-10 at about 25% strength.

Cugal, your seedlings look awfully small but I wouldn't worry yet. Fertilizer needs to be a consideration shortly after germination occurs.

Southcountry uses a product with an exceedingly high PHOSPHOROUS percentage very out of balance with the other elements. It used to be thought that PHOSPHOROUS stimulated roots and flower induction. There is no scientific data to support this. Find a soluble fertilizer, preferably one without an excess of any of the three major elements.

EDITING NOTE : Please forgive my inadvertent error regarding the erroneous use of potassium instead of phosphorous. Phosphorus (always the middle number in a fertilizer ratio...N P K) is what I meant. It is the mineral often added in too large amounts to promote bloom, faster root development, etc.

This post was edited by rhizo_1 on Wed, Mar 13, 13 at 5:35

Mine are under 4 ft. shop lights in my workroom which is kept cool (60 ish) though warmer under the lights. It will be another month at least before they can start going outside here. I use a balanced soluble fertilizer (12-15-12 ?), diluted about 1/4 strength every time I water.

I have a group of waves that are about a week older than these (yellow Horizon) which are already shooting out runners. I just potted them up to 9 oz cups and snipped off the runners to root. I actually saw a bloom starting to form.

The wave petunia seeds are a bit pricey, so I start them early and then quadruple my numbers by rooting the cuttings.

I used to be pretty ho-hum about petunias, because of the slim selections available at the garden centers here. I have become much more enthusiastic since I started growing them from seed.

Thanks folks! From what I'm reading, I need to be fertilizing...... I've used some liquid seaweed (0-0-5), but no NPK. I'm using ProMix BX & thought it contained enough nutes to sustain them until they were potted up......... Apparently not.....

Would one teaspoon of 20-20-20 per gallon of water work? That computes to 264 ppm N, 116 ppm P, & 219 ppm K

rhizo_1 thanks for bringing up the old vs new thoughts on fertilizer. Around here it is all old school. In your opinion how detrimental would too very high levels of P be in a soilless media?

Regarding when to start fertilizing it is my impression that seedlings have the nutrients to sustain themselves for 4-5 days after which we need to feed them. Is this correct?

cugal, I looked at my notes and the first wave of petunias I planted had a huge growth spurt at 17 days after germination. It was also, possibly coincidentally, a day after I increased the fertilizer mix to about 25% recommended.

Thanks to everyone on these forums for good discussions. It is my first time expanding to sowing flowers and I am finding them a touch more delicate than veggies.

Take it from someone who has grown petunias for more years than I care to remember. Your plants do NOT need fertilizer yet. To fertilize now will set your plants back. Petunias come up, grow a little and seem to just sit there for a while. Then all of a sudden they take off and seem to double overnight. From the look of yours I'd say they are doing fine--just have patience and you';ll have great flowers

Thanks so much dowlinggram! Experience is indeed the best teacher! In the world of propagation, it's far too easy to over fertilize. Ask me how I know this.......... LOL I was reluctant to apply even very diluted fertilizer to my Pets at this point. I'm a fan of digdirt (Dave) (in Growing From Seed) & he has always said that seedlings started in a good growing medium do NOT need additional nutes at this juncture...... With 50 years of growing experience, I'm inclined to think he knows what he's talking about!

SouthCountry, please see that I edited my earlier post. I had Potassium in my head yesterday haviing found out that I have a deficiency. Anyway, your fertilizer has a ratio of 10-52-10. That's the percentage of Nitrogen, Phosphorous, and Potassium....in that order.
I am so sorry for adding to the confusion!

Phosphorous excesses throw soil and plant chemistry way off, causing deficiencies of other essential elements. Seedlings may be especially sensitive. The need for a fertilizer with a much higher P percentage does not exist....and the fertilizer manufacturers know it. You'd be far better off using a product with a low analysis. "Bloom Boosters " and "Starter Fertilizers " are marketing gimmicks. Most of us have fallen prey at one time or another. Chlorosis would be an early indicator of problems possibly caused by your fertilizer.

Seedlings require a source of nutrition at all stages of development. As the germination process begins...usually with the introduction of water...the nutrients stored in the seed remetabolize and become the source of food for the young, developing embryonic plant. The seed continues to provide sustenance until....it can't anymore! It gets all used up.

Luckily, plants have evolved so that the timing is pretty darned exact. Once a plantlet sees the sunlight, photosynthesis is able to kick in. Growth and development also requires dissolved minerals! In nature (in the ground), tiny roots can source the ample minerals available in the soil at that point. But what about the soil-less (peat based, usually) media favored by most of us?

Low doses of soluble fertilizers need to be provided pretty early on. I begin as soon as I see leaves. Since the seeds of so many annuals are very tiny, without a lot of storage capacity, an outside source is needed pretty darned soon after the leaves emerge and the plant begins to grow. Our peat based mixes contain zip, as far as dissolved minerals go.

Without a readily available mineral source, young seedling development may be hindered. Those elements are required for every single physiological activity. Less is best.

If the growing set -up doesn't allow for water drainage, or the medium is very fine-textured, then great care must be taken.

Edited to remove double post!

It's a good time to remind ourselves that there are many ways to produce healthy, fabulous plants. Just as many as there are variables in our individual home based set-ups.

There are some factors that simply can't be changed, however. Plants grown even in a good soil -less medium cannot survive on air and water alone....even seedlings. Perhaps I should use the word "thrive ", rather than survive.

Though I've never considered the "been doing it this way for a jillion years " something to brag about in this very changable field, I find myself stubbornly adhering to methods that have been tried and true for me for many years of active professional and just for fun practice.
:-) Though I hope always to remain science /fact based in my work, and have altered countless practices accordingly, I still cling to others because they "work for me ".

My seedling medium is a rapidly draining one. I water from above with a misting/fogging nozzle until excess water drains from the bottom. The oxygenated water is a boost for plants (all plants), but anyone growing in a porous medium must pay attention to the nutritional requirements of their plants.

Porous mixes produce plants with very well branched and vigorous roots systems. That kind of root system will result in sturdy plants, very fast to flower even before planting. And that kind of mix doesn't support algae, damping off diseases, or fungus gnats.

This post was edited by rhizo_1 on Wed, Mar 13, 13 at 8:19

This looks like the perfect scenario to do a little experiment. Do fertilize ,don't fertilize yet.Why don't you add a little weak fertilizer to 3 or 4 & mark well & see if you see a difference?
Rose

I think Rose may have a good idea........ Being very inexperienced, I have little personal data to refer to & rely mostly on info garnered on the internet...... That said, I've fertilized a few Pets with a weak solution (300 ppm) & I should have my question answered in a few days..... I'll keep GW posted.....

Rhizo - I would love to hear what your soil-ess mix is.

Do you make up your own? or do you buy a specific brand?

I have used a variety of packaged seed starting mixes, sometimes adding additional pearlite and or vermiculite, and havent noticed a big difference.

I tend to get some algae growth no matter which, but I dont have good air circulation.

I have some petunias that have volunteered, both in a basket that had some large ones, and in the ground, where I had some of the VIP type. Both have grown quickly to blooming size with no fertilizer.

Mandolls, I use one of the excellent products from Fafard. The company makes a line for the retail market and those should be avoided. Their Professional line of mixes contains three categories...Light Weight, Middle Weight, and the Heavy Weights. Google for information.

Fast forward to the Heavy Weights. Their #3 mix is an excellent choice for small cell packs and other small containers. I use it that way....filling, wetting, and poking holes in the flats of cell packs in preparation for seedling transplant.

I use a Middle Weight for the germinating flats...still coarse textured but smaller particles. Remember, I germinate seeds separately....two germination flats evolve into 20-25 flats of cell packs (18 plants each). One bag of that lasts a few years. Even though seedlings don't stay in it for very long, this stage of development is very important. A porous, fast draining medium helps the plants establish the kind of root system we want.

Plus, I have a small amount of a very fine textured germination mix
that I use to dust over the prepared seed flat...especially the little furrows I press into the surface. Plain peat moss can be usex for this purpose. I'll also dust a layer on top of those seeds requiring a dark environment for germination. I've had a small bag (4 quart?) of that stuff for years. Ha! I just remembered that I moved it to Alabama with me over ten years ago. It does serve a purpose in those germination flats: soil to seed contact.

Just for information purposes, the Fafard products I use in the greatest amount are the Nursery Mix, #52, #52L. That's what goes into all containers...houseplants, baskets, outdoor containers, rooting of any and all cuttings.

You will have to sweet talk a privately owned nursery /garden center into sharing their own stock with you or special ordering it for you. One of my gardenweb friends talked to a nursery manager about it per my recommendation and was ushered into their staging area where several pallets of Nursery Mix was stockpiled for their own use. I've never been refused.

The Fafard products are ready-to-use. No improvements needed.

Thanks so much for the info Rhizo!! I appreciate the detail you went into. I will definitely look into this.

Thanks rhino_1 for some excellent information. I live in a fairly remote (as far as population goes) area and almost everything is done "old" school. Until getting into sowing flowers I have just done as everyone else did. Thanks again.

At a commercial level do you move petunia (assuming like other plant) seedlings straight from the sowing flats to pony packs (6 per) or do you go to 72 cell flats then pot up (if it really is up since density per flat is the same)?

Thanks

This post was edited by SouthCountryGuy on Thu, Mar 14, 13 at 16:03

South...please know that I am no longer 'in the business '. This is simply backyard fiddling.

I prefer to use #1801 cell packs, which give me 18 nice sized transplants. I have some smaller sized inserts (#804s which give me 32 plants), but I rarely use them. They fit into the #1020 trays, which is also what I use as my germination flats.

After germination, I unplug the heating cables and give the seedlings a
couple of days to harden up before transplanting. Then, they get plopped into the prepared cell packs which are already inserted into their plastic trays. Done.

So...the process consists of a few days of germination...I limit myself to two or three germination flats. Each may have up to 200 seeds ( not all of which are used) depending upon the size of the seeds. They're sown in tidy little rows, labeled at the end of each variety so I know who's who.

I end up with a lot of plants. If I only wanted a few, I'd probably change my process....but maybe not. It's easy, streamlined, and the end product surpasses anything seen in the garden centers. That's kind of nice.

Feel free to email me if I can be of any help. Remember, there are many paths to the same goal.

Thanks, rhino_1. I wish I could fit all my needs in #1801's. I struggle to make this venture profitable with 6 plants in #1201's (pony packs). It is scary as I am fitting into our throw away society where quality is being surpassed by quantity. Ug...

Here is a picture of some of my petunias seeded Mar 5.They were sown in a thin layer of seed starter over the dreaded Miracle Grow LOL. I think tiny seedlings do better nestled in a community container until they are big enough to go into 4 inch pots.
Rose

Rose, those are sturdy looking little seedlings! They'll be easy to transplant.

Wow 715rose! Those rival mine that were sown on 2/19....... I've started some other annuals as a safety net, in case my Pets don't pan out......... It's not looking favorable........ I've moved them to my heated GH, but our forecast is for more cold weather..... :(