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Artichoke germination

milehighgirl
14 years ago

I planted 25 Imperial Star seeds 10 days ago in my egg incubator. The temperature of the soil is 85 degrees. Within a couple of days I had three sprouts, and now nothing. I've unearthed a few of the seeds and they don't look like they are decaying or anything.

Before I planted them I soaked them in warm, 100 degree water for about a half an hour. The seeds are in seed starting medium.

Should I quit waiting and assume the won't germinate, or were the first three just anomalies?

They are from Fedco. The package says it was tested at 75% germination.

Comments (25)

  • sunnibel7 Md 7
    14 years ago

    First I'll say that I've only germinated artichoke once and overall, I'm no expert. But my feeling is that that soil temperature sounds rather high. Did the package say to germinate them at such a warm temperature? Perhaps if you lower it 10 degrees? I did germinate a number of cardoon at around 70 degrees, no presoaking, a few weeks ago. I don't know how similar the two really are. Maybe do an internet search for artichoke seed germination temperature? Or maybe they are just long, uneven germinators. :)

    Cheers!

  • denninmi
    14 years ago

    Milehighgirl -- I had similar problems with my first batch last year. I kept mine on a heating mat at a soil temp around 74 degrees. I got a few to germinate initially, then nothing.

    I posted about this same ? on another forum. Someone replied and told me that they need alternating day and night temperatures in order to germinate well.

    So I tried this with the second batch, and also with the ones from the first batch that hadn't germinated. I got much better results. Even a lot of the ungerminated seeds from the first batch sprouted.

    85 is kind of hot for most seeds, except maybe true tropicals like banana seeds. I'd cut the soil temp back to about 75, which is warm enough for most everything, and then put the whole thing on a timer so the heat is on 12 hours then off 12 hours. Or, just unplug it every night and plug it back in in the morning.

    Let us know if this works for you. It did work for me last year. I haven't started any yet this year, but will probably do so in the next week or two, certainly by March 1st at the latest.

  • naturegirl_2007 5B SW Michigan
    14 years ago

    They germinate better at lower temps. Johnny's Selected Seeds recommends 70-80 F. They also state "Where winter low is abonve 14 F (-10C) sow seeds in fall, harvest in spring"....another clue that they don't need or like hot temps. UCDavis cultural sheets indicates they do not germinate well, especially at high temps. The linked article shows 60-70 F might be even better for germination. I don't know if moving them to lower temps would help now or if they are goners.

    Here is a link that might be useful: Artichoke germination temps

  • milehighgirl
    Original Author
    14 years ago

    Well, I never thought about the day/night difference! I guess basically I was lazy and tried to germinate them with my peppers, which do seem to do well at 85 degrees.

    I'll take them out of the incubator and see what happens. I'll keep you posted. I do have another package of seeds, but I'd rather figure this thing out without using them all.

    Thanks for your advice!

  • lilydude
    14 years ago

    I planted some Imperial Star and Emerald on 1/26 in soil-based potting mix at 60F. 60% of them are up, and more are coming. I am growing them on at 60F under lights.

  • Belgianpup
    14 years ago

    They can take a month to germinate. Yes, lower the temps, as high temps can inhibit germination.

    Pinch a couple of the seeds and see if they are mushy inside.

    Sue

  • cabrita
    14 years ago

    Two comments.

    First one, you might all be too high (I mean temperature wise). Artichokes are winter plants to us, spring/fall plants to continental climates, but they only grow in the mediterranean climates. I have been germinating my artichokes outside, where day temperatures are below 70 and night temperatures between 40F and 50F. I have gotten 9/10 germination from romanesco, 9/10 from imperial star (then some critters ate one), and 0/10 from violet star. The two varieties that germinated did so within 2-3 weeks. I have just transplanted 8 of them in the garden (I grew in pot since I am trying different varieties and wanted to keep them sorted). I am leaving the others as spares, since some will be eaten.

    Second, I have gotten really low germination out of Fedco seeds, even if the packet says 85%. Recent examples include two eggplant varieties and many cauliflower varieties. I did not get artichoke seeds from Fedco, I got them from Reimer seeds. Mixed reviews since 1 of the 3 packets did not germinate at all. Trying 10 more seeds inside just in case it is a warmer weather variety?

    My other artichokes are globes, I think of them as our natives, I propagate them from cuttings. Just observing their growth patterns, they look sad and tired in the summers, come back to life in the late fall, now they are growing like crazy, I hope for some artichokes in April. After April/May they die back. They are a winter crop.

    I hope this helps, good luck and enjoy them!

  • ralph31558
    14 years ago

    I started my Globe seed in cell packs, i used a seed growing medium which i dampened with warm water and inserted a seed in each cell,I then put the cell pack into a clear plastic bag to hold the moisture, put the pack into a small cardboard box closed the lid so that there would be no light and set it down on the frig. and they will sprout.I had done the same with cardoon and i have alwready re planted them in larger containers and the are now about 5 " high.

  • promethean_spark
    14 years ago

    I planted fedco's imperial star last spring outside (50/70'F) and got about 2/3 germination.

    Artichokes grow a lot of roots for the size of the plant, so pot them up or get them in the ground early.

  • milehighgirl
    Original Author
    14 years ago

    I've taken to heart a lot of what's been said. To be honest, anything mediterranean translates to mean "warm", to me, since I'm in Colorado, So, artichoke being a cool weather plant is a new idea completely!

    I have taken them out of the incubator, but I'm having trouble finding a good place for them now. I tried them on an East-facing window pane and day-time the soil would reach 80 and at night it would get down to 60 or just under. This seemed quite extreme to me, so then I tried ralph31558's method and put them above the refrigerator, but honestly it was only 62 there. We just got a new refrigerator and it really doesn't put out much heat at all.

    So....is it better to have the day/night difference, or the more moderate temperature above the fridge? I could also set up a florescent light above them to give them a little more heat.

    Any more suggestions?

  • sunnibel7 Md 7
    14 years ago

    Here's a link to some tables showing the average weather conditions in Italy (north, middle, and south), including average highs and lows by month. I would think it would best be described as temprate. Northern Italy compares with Northern Virginia pretty well (but I don't think they get the humidity!). Anyhow, you would think of Virginia as warm too, except it's not always summer here, as the remaining foot of snow out there keeps reminding me. Maybe looking at those tables will help you get a better picture of their native habitat? I think it bodes well for my cardoons!

    Cheers!

    Here is a link that might be useful: Average Temperatures in Italy

  • cabrita
    14 years ago

    milehigh girl: our daily thermal swings run 30 to 40 degrees. To give you an example, we reached 79F yesterday, but this morning the thermometer read 48F. Night and day fluctuate but 30 degrees F, unless it is raining and this is rare. All the artichokes are outside and looking good. Not sure if they require the large temperature fluctuations or just tolerate them. However, in addition to looking at the weather in Italy, you can look at the town of half Moon bay in coastal California. Half moon bay is the US artichoke capital, even though I think they call themselves the 'world' artichoke capital. In any case, artichokes grow very well there. They have terrible weather (always foggy!).

    When you put them on the ground, choose a spot that will get some shading in the summer if your summers are hot. They do not like a lot of direct sun, but do require some sun. Think coastal California.

    One of my 8 got eaten by some critter, the other 7 little babies are all doing well. I can't wait to see what they look like when grown.

  • dicot
    14 years ago

    And gophers love them, so consider chicken wire or something else underneath if that is a problem in your area.

  • milehighgirl
    Original Author
    14 years ago

    Just a note to say that finally the rest started to sprout. I have 18 sprouts now. I wonder why there was about a two week delay between the first three sprouts and the rest. The germination rate is 60%, and it looks like they're done sprouting, but who knows! I won't give up on the rest.

    I found that next to my fridge, on the counter, the soil would stay at about 68 degrees, so I left them there and had some luck!

    Thank you all for your encouragement!!!!

  • cabrita
    14 years ago

    {{gwi:20342}}

    This is exciting, 18 seedlings! here is a picture of a Globe in its second year. I hope to get some chokes from it this year. They make a striking addition to an edible landscape.

  • christine97
    14 years ago

    I started some globe from seeds and I didn't keep track of how many I started and the amt that germinated, but I would say it was high. We have a bay window that faces west in our living room with a pellet stove in that room. the room can get warm during the day and very cool at night. I did read somewhere that they do need a low temp for a number of days in order to germinate so perhaps that is why some are coming up later than the others.

    Thanks cabrita for the pix. I have never seen an artichoke plant, they are beautiful.

  • cabrita
    14 years ago

    {{gwi:20344}}">
    {{gwi:20346}}">

    Artichoke buds sprouting from the plant pictured earlier, a green globe.

  • mauirose
    14 years ago

    Nice!

    So far no buds for me. i'm not sure if i should count this as year one or year two since the sprouts spent most of last year in small pots. i probably don't have enough elevation to grow these but it's fun to try.

  • christine97
    14 years ago

    That is awesome lookiing!

    Mine are doing good outside, they even seemed to do ok when the weather dropped to the 30's and I forgot to cover them.

  • christine97
    13 years ago

    Hello everyone!

    I have one single artichoke bud that is small. Do they continue to grow larger as time goes on. It appears that the leaves on the outside might be starting to open, but I am not sure since this is the first yr I've attempted to grow them. It has been hot and I haven't been watering them, but I have read that watering is important when it is hot. So I will start doing that.

    Thanks

  • don_in_ct
    13 years ago

    I'm trying to grow Imperial Star Artichokes here in Connecticut this year, and thought I should try to post my results. This is the first post. On 3 February, I planted 16 seeds purchased from Sustainable Seed Company. They went into two Burpee 10 coir pellet seed starting greenhouse kits (four pellets were used for cucumber seeds). The two seed trays were covered with the clear plastic lids and placed in my south-facing bedroom window. I estimate that on sunny days air temperatures in this area of the room are in the 80s. At night they cool into the mid 60s. The four cukes sprouted in less than three full days. The first artichoke seeds sprouted by the 9th, or approximately six days after planting. Today, February 12th, a total of 11 have sprouted. I doubt more will sprout, but if they do I will mention this in an update.

    Today, still the 12th, I have potted up the 11 seedlings into 3" square Burpee fiber pots, as their taproots have already grown out of the coir pellets by an inch or more and were about to start growing into neighboring pellets.

    I have been loosening and/or removing the clear lids during the day depending on the intensity of the sun. Doing this, or removing the lids entirely is clearly necessary, as after three days I noticed a few wispy silk-like strands of what looked like a fungus growing on a couple of the pellets. They disappeared once the humidity dropped (but the seeds in these pellets have not sprouted).

    The next steps will be to 1) pot up again as I'm sure the seedlings will outgrow the fiber pots quickly, and 2) conduct the vernalization process in March/April, which is required to trick the perennial artichoke plants into flowering the first season.

  • DrHorticulture_
    13 years ago

    As Don says, don't forget the vernalization process. It is vital. Non-vernalized plants will sit in suspended animation all summer, refusing to grow. 32-40 degrees F is best.

  • dicot
    13 years ago

    I've got 5 now, think I might need a few more. Such an easy plant here, I just need to stay on top of the aphid and earwig issue with soap regularly, the earwigs sure love building nests in the leaf junctures.

  • Beeone
    13 years ago

    So how do you accomplish the vernalization? Nights are below freezing early in the spring, but if the plants are brought in they will be at 60-70 degrees? Do you keep them in a refridgerator without light?

  • aquameo
    12 years ago

    Awesome thread!

    Planted my first batch of 18 mixed seeds of "green globe" and "purple of romagna" from Botanical Interests in 2" soil cubes indoors. Hopefully I'll have a good success rate.