Gordon Summerfield on Growing Bulbs

Mary Sue Ittner msittner@mcn.org
Sun, 12 Oct 2003 14:57:27 PDT
Dear All,

I promised you I would tell you a little of what I learned from Gordon 
Summerfield, an expert  grower of South African bulbs from his talk 
(Creating the Right Environment and Conditions for Growing Bulbous Plants) 
and my several conversations with him. So here is my attempt.

Gordon took up growing bulbs seriously after he retired, but he told us he 
had been growing for 15 years. Many of the things he had read in books 
didn't turn out to work well for him. He now grows with what he calls a 
common sense approach. And he spends a lot of time looking at his plants, 
pollinating them, collecting seed, cleaning seed, putting information on 
his data base, etc. He says he has never been so busy in his life! He also 
plays golf, but most of his energy goes into managing his collection. I 
seem to recall the figure of 3000 pots. He grows a lot of different 
species, but they are mostly from the winter rainfall area. He seems to 
have a fondness for Gladiolus, Romulea, and Lachenalia although we saw many 
others in bloom as well.

Along with three other IBSA friends (Berger van Eeden, Rossouw Malherbe, 
and Henry Pauw) Gordon drives his four wheel drive out into the Veld to 
search for plants. They make friends with farmers, get permission to go 
exploring on their property, and then when the flowers are closed stop for 
tea and conversation. They have found many an unusual plant or form this 
way and Gordon has the reputation for being a good spotter and for 
remembering where they saw plants when they come back to collect seed. So 
some of the things he grows were collected from their travels. Gordon also 
sells his bulbs and seed that he has saved from his plants. Here is a 
picture my husband took of Gordon and Bob Werra the night of the IBSA 
dinner. Gordon is the one pointing his finger.

First he suggests (and this we have talked about a lot on this list) that 
you try to duplicate the natural growing conditions of the bulb. To do this 
you need to know about where they grow.

Mix and Watering: Gordon uses a mix of about 1/2 good potting mix and 1/2 
grainy sand. He used to try other things but found that his plants 
benefited from the added nutrients in the potting mix. The grainy sand, and 
we are talking coarse sand, helps with drainage (translated air filled 
porosity). Many of the winter rainfall bulbs like acidic soil, but not all 
so again it is helpful to know where they grow. Freesia leichtlinii grows 
in limestone for instance. Summer rainfall bulbs often need a higher PH so 
adding lime to your mix may be helpful.

He feels that there is a myth about plants rotting from too much water. If 
your soil mix is correct, you cannot over water he says. It is much worse 
to let your plants dry out too much. In spite of saying you can't 
overwater, he does believe that leaves may need protection, especially from 
the early morning dews. He found this to be especially true for 
Lachenalias, Romuleas, and Gladiolus. So he grows many of these under cover 
of a high roof with open sides.
Here is a picture that shows his pots and the structure:

Both he and Alan Horstmann told me a lot of Romuleas grow in very wet spots 
and you couldn't give them too much water. Species he mentioned were 
komsbergensis, tortulosa, atrandra, diversiformis, stellata.

Plants like Daubenya and Massonia need good light however. Good light, but 
protection from the dew will reduce crown rot and fungal diseases. Watering 
from the bottom will help as well. (Just a note--The thought of watering 
all those pots Gordon has from the bottom was mind boggling. He didn't seem 
to be doing it for very many, so perhaps he had learned which ones were 
crucial to water this way.) He advised me that some of the Lachenalias from 
very dry habitats that I have successfully killed should be watered from below.

As for summer water during dormancy he thought corms did not need it, but 
bulbs with perennial roots would. If his plants have not started growing by 
April 15th he gives them a good soaking.

Gordon advises a southeast facing aspect (that must translate to northwest 
in the Northern hemisphere?). The late sun is harsher and harder on your 
plants. Some plants open facing south and never turn around so you need to 
site them accordingly.

One very interesting point that I don't think I'd heard stressed before was 
how deep to plant. He advised to observe in nature how deep the bulb grows. 
Most of us can't do that, but we can see when we repot where the bulbs are. 
If you plant at the wrong depth, the plant won't flower until it is at the 
correct depth. So if every year you repot and change where they want to be 
you may never get them to bloom. If they are planted too deep you may lose 
them because they won't grow well enough to survive over time. It is best 
therefore to err on planting too shallowly. You won't lose the plants; they 
may just wait to bloom until they have pulled themselves down to a more 
comfortable level.

When you have as many pots as Gordon does there is no way you can repot 
every year. He has discovered which plants need repotting and which do not. 
Otherwise I think he observes during the growing season to decide which to 
repot the following season. I had asked him over dinner about why the Cape 
Encyclopedia advises not disturbing Lapeirousias. I have not had good luck 
with them and have been repotting them most years so wondered if that was 
why. He said they liked to be planted deeply (which was news to me since 
most are not very big). Bulbs with a flat bottom like Lapeirousias are best 
planted at a 40 degree angle as it is easier for their roots to go down in 
that position. Words on Moraea--a lot prefer not to be repotted. Exception 
is gigandra which produces a lot of corms from stolons.

Fertilizing--He believes that it is a myth that South African bulbs should 
not be fed. He advised avoiding super phosphates which he says many of the 
bulbs hate and feels bone meal has no value at all. Also he doesn't think 
foliar feeding is helpful. Here is his formula for feeding:
Magnesium sulfate--If leaves are yellow or the tips brown need this
Ammonium sulfate--Provides nitrogen. He says contrary to opinion bulbs need 
Potassium sulfate--Helps the new leaves, if they are purplish they need this
Kelp--This helps with formation of the bulb for the next season. He adds 1 
Tablespoon to a gallon of water in the middle of the growing season.
Both he and Henry Pauw add small amounts of these and dissolve them in 
water instead of mixing them in the soil.

My notes mention problems with mealy bugs, aphids, red spider mites so 
these beasties seem world wide. He told us to cut down the incidence of 
rust by treating the soil, but I didn't note how.
As for plants that look sickly, he would not toss them out without first 
trying to help them by adjusting the watering schedule or feeding them. 
They may just be stressed and not have the nutrients or trace elements they 

The first day we saw Gordon he told us he had been out pollinating. That 
was surprising since it was pouring rain. But he said it was a good day to 
pollinate (obviously a lot of flowers would be closed, but things like 
Lachenalia which he has a lot of and which are under cover would be open.) 
The pollinators would not be out and he could accumulate pollen before they 
got it. Gordon is very careful to avoid hybridizing his seed so he wants to 
be the one to pollinate his flowers. He takes barbecue sticks and wraps 
them himself with cotton and dabs them with glycerine. Others might use 
cotton bobs but he likes the different widths he can get by making his own 
and that these sticks are longer and easier to place in the pots. He 
collects the pollen on the stick and then places that stick in the pot with 
those plants he has gathered pollen from. Then on the next warm day he can 
go back and pollinate the flowers. If he ends up with hybrids (something 
perhaps that comes up in a pot), he doesn't throw them out, but puts them 
in his garden to enjoy. He just doesn't want to sell bulbs or seed unless 
he can be sure they are what they are supposed to be.

The picture below was taken that day in the rain when Lauw de Jager, Patty 
Colville, and I are looking at his flowering bulbs under the cover. He has 
on the blue coat.

Gordon has found that bulbs that are rescued and therefore dug and without 
soil and out of water  or bulbs that may get inadvertently knocked over by 
animals that you later find lying on the ground can be transplanted without 
any shock if you treat them by soaking them in ordinary water for 24-36 
hours before you replant them. It is the roots you need to hydrate. You 
keep the leaves dry and the bulbs and corms out of water although this is 
not so crucial with corms which can tolerate being wet. Once they are 
replanted water them well and leave them. Do not cut off the foliage. If 
the plant has already lost its leaves, it can be stored dry.

Seed Advice--I have not always been able to get good germination from 
Spiloxene so I asked about it. It had seeded itself about in his pots so 
obviously it shouldn't be hard to grow. I mentioned in another email that 
Gordon has an amazing collection of different forms of Spiloxene capensis. 
One of these days I'll get pictures of them on the wiki I hope. He 
suggested I sow the seed (which is tiny) uncovered without sand or grit and 
then cover the pot with plastic wrap to maintain the moisture. Water from 
below so as not to disturb the seed. When the leaves start to emerge you 
can anchor the seed with a little sand. The same procedure can be used for 
other tiny seeds like Ornithogalum. He advised patience and leaving some of 
the small ones in the same pot for a long time.

This final picture shows the room that Gordon has managed to talk his wife 
into letting him have to manage the business and store his seed. He has not 
only written the name of the plants but the place where the original seed 
was collected and he is keeping seed of the same species therefore 
separated. That's me behind him smiling when I saw all those containers of 

Hopefully some of you will find this interesting and helpful. Others may 
disagree with some of his findings. This is what works for him. Hopefully 
I'll be corrected if I got any of this confused. Lauw tried very hard to 
persuade Gordon to join this forum, but I could see that he wasn't going to 
succeed. Gordon doesn't feel he has time. He did say he'd answer questions 
if anyone had them and we could send them through his daughter. Lauw 
volunteered to be the contact person for the group. A very wonderful 
quality about Gordon is that he really does want people to be successful 
growing bulbs and he is willing to share all his secrets. Sometimes experts 
keep their secrets to themselves. And he says he wants to know if people 
have success with his seeds or not. If they don't have success, there has 
to be a reason and he is eager to change this.

Mary Sue

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