Topic: Whitefly and french marigolds.

[carolinej]

Hello :)

I have a  greenhouse, which has been planted with peppers cukes, tomatoes, french beans and calabrese.

Alongside the tomatoes on the one side I planted french marigolds. I ran out before I could get to the other bit by the calabrese.

A few days ago, the calabrese were infested with whitefly, but nothing else. I pulled the plants up, and the whitefly went everywhere. I was dreading them spreading to everything else.

Two days later, and there is no sign of whitefly.

I just thought I'd mention this for anyone who was a bit sceptical about marigolds driving away whitefly.

I am going to grow millions of them next year (marigolds, not whitefly ::))

cj :)

[Tee Gee]

Thought I would mention that there are basically two types of 'whitefly' ..................indoor & outdoor hence the reason you saw what you saw with the Calabrese, these were the 'outdoor' type and I don't think growing marigolds will make any difference to this type.

Regarding marigolds keeping whitefly at bay (indoor type)!!

I am a bit of a skeptic on this one, I see it as a chicken & egg situation??

OK we see that whitefly congregate on marigolds rather than some other plants but did the whitefly appear because there were marigolds in the vicinity?  and would they have come into the greenhouse if there hadn't been any marigolds??

I think the best way to establish this is; Do not plant marigolds in the greenhouse but grow a few in pots outdoors. Then if whitefly do appear in the greenhouse fetch in the potted marigolds and see what happens??

Sorry for being so skeptical thats just me I am afraid!!

[valmarg]

TeeGee, we have been growing french marigolds, planted in the pots/growbags together with the tomatoes.  My understanding is that the tomato plants take up 'some substance' from the marigolds that white fly do not like.  It does not affect the taste of the tomatoes, but keeps the tomatoes white fly free.

In the c. 20 years we have been using this form of companion planting, we have never been troubled with white fly on any plants in the greenhouse.

Based on our experience, I would thoroughly recommend it.

valmarg

[Tee Gee]

Point taken Valmarg but as I said 'I am a skeptic' ;D

But you have set me thinking!

Strangely enough I too have been growing Tomatoes 20 + years and never had white fly but the difference is I don't use marigolds

I don't want to appear flippant but as a matter of interest; do you get white fly on your marigolds?

I ask this as a serious question if only to prove to myself and possibly others it might be a chicken & egg scenario i.e. would the white fly come if there were/ were not marigolds in the vicinity?

I feel the true answer is one of those imponderables like the chicken & the egg.

At least you and I have found both systems work does everyone else?


By the way! the point that I was mainly discussing in my previous reply was about indoor/outdoor white fly and there relative treatments.

Marigolds ( so far as I know) would not have the same affect on outdoor white fly, even hard frost and snow won't move these!

[telboy]

I tend to agree with Tee Gee,
White fly is now beginning to show, but one can spray but not eradicate.
It is a pest but does not seem to harm the host plant. Due to the 'soft growth' of late, it could be worse than in previous years. Your 'Darlek' could still be a host from last years composting.

[valmarg]

Tee Gee, before we started planting the marigolds in with the tomatoes we used to be plagued with white fly, swarms of the little sods.  Since using the marigold companion planting method, no whitefly whatsoever!!

You can be as sceptical as you like, but in our case this method has worked for many, many years.

No, we don't get whitefly on the marigolds, as I have said, whitefly do not like marigolds!!

If it aint broke don't fix it, and if it works, don't knock it!!

valmarg

[Tee Gee]

I'm not knocking it Valmarg far from it, I am just having difficulty putting what I am thinking into words.

I think I see where this is going and that is if there are marigolds in the vicinity white fly will keep their distance.

What I always thought was; that if there were marigolds in the vicinity they 'attracted' the white fly but obviously I was wrong they don't. But not having used this method I wasn't to know.

Incidentally my way of keeping white fly at bay is not letting the growing area get too dry, this method also helps to keep 'spider mite at bay because they too like it very dry.

Thanks for putting up with my ignorance.... TG

[valmarg]

OOOH Tee Gee, the one thing I would never accuse you of is ignorance.

You obviously have really good conditions in your greenhouse, so that you are never troubled by whitefly.

All I was trying to do was give a 'testimonial' for the companion planting of french marigolds in the containers with the tomatoes, to avoid/get rid of whitefly, for anyone who was plagued with them.

Having been plagued with whitefly in the past, we have found it works.

I'm with you, on being sceptical with other companion plantings!!

Planting nasturtiums alongside brassicas so that the cabbage whites lay their eggs on the nasturtiums, rather than the brassicas.  I don't think so.  The cabbage whites will lay their eggs on anything a-going.

One I havn't tried, is mixing spring onion seeds with carrot seed, to deter the carrot root fly.  I'd have to say, I think the smell of carrot would be stronger than spring onion.

valmarg

[maui_tomato_man]

I'm growing a few different species of tomatoes at the moment - Brandywine, Better Boy, Big Boy, Beefmaster,
Supersteak, Kewalo, Roma, and some bell peppers - all in pots, 7 gallons to almost 15 gallons.  The plants are about 1 to 2 feet tall at the moment, still a good 50+ days away from fruiting probably.

This is my first time to jump into tomatoes and I'm trying to do everything right.  I discovered this bit about marigolds and tomatoes in the last few days and want to try it as my tomatoes are getting hammered by leafminers.   So I guess I have 2 questions.
(1) Anybody know if marigold companion planting will banish leafminers?  I've been using neem oil but the leafminers don't seem to go away, although it may have slowed them down a bit. It's hard to tell.

(2) Which species of marigold should I use?  I'm hearing French and African, but which species?  Or will any marigold species work?  They'll need to be small enough to plant in the containers with the tomatoes, i.e. not the marigolds that grow up to 4 feet.

Ok, that's more than 2 questions.  :P

I'm open to all advice.... thanks much.

[carolinej]

I only know that the ones I use are French Marigolds. They are about a foot high. I have planted them in the soil of the greenhouse border.

In my other greenhouse, I had a tray of marigold seeds that didnt germinate. After about 2 months, I used the compost to top up a black bucket with a tomato plant  in. Now I have noticed small marigold plants growing in the pot. I am leaving them in there to see how they do.

I feed the tomatoes with pelleted chicken manure, which is in the flowerpot I have sunk in the soil next to the plant. When I water through the pot, some of the manure goodness gets washed into the soil, so I dont think I will get a problem with the marigolds taking up too much of the goodness in the pot.

Saying that, there is a fair pong in my greenhouse from the manure, but I am trying it as an organic alternative, and it seems to be working. I have 3 plants in the conservatory that I am using the chicken manure in too, but I have covered the manure with a layer of compost to keep the smell down. :o

cj :)

[valmarg]

maui_t_m, there are several varieties of marigolds, but my preference is for the small french varieties.  The seeds are cheap, and they germinate very easily.  African varieties are very large, and the seed is very expensive.

The other marigold is 'pot marigold' aka calendula.  I just don't like these, and cannot vouch for their being efficient in the reduction of whitefly.

valmarg

[maui_tomato_man]

Thanks for the advice.  I'll just find any small French variety and maybe the pot marigold too.  Hopefully that will do the trick.  That's a good idea about sinking the pot into the soil and letting the manure leech out when you water.  I'm using pelleted chicken manure too.  I just mixed it in with everything else.  Incidentally, my mixture is: 

50% pine bark mulch (very small bark pieces)
15% orchid bark (small)
20% SuperSoil (has Peat, Poultry manure among other things)
15% perlite
Couple of small handfuls of pelleted chicken manure
just a titch (very small handful or less) of garden lime (calcium)
an even smaller titch (pinch or two) of 0-20-20 Gaviota fertilizer (made here in Hawaii)

I also have have a fish emulsion that I alternate with Miracle-Gro Tomato Fertilizer (18-18-18 I think) every couple of weeks. I'm careful with the fertilizing as I have no idea when I'm on the verge of burning the plants.

After poking around on the internet and pulling ideas from various different mixtures, this is what I decided to try.  The %s are all approximate, I just eyeball everything.  Also, the pine bark mulch is the cheapest ingredient on the list.  The Orchid bark is expensive, but the SuperSoil isn't bad.  Also, I already have some mushrooms growing in a few of the pots with the tomatoes.  Presumably they came in with the tree bark - not sure.  I'm told this is a very positive development.

[carolinej]

an even smaller titch (pinch or two) of 0-20-20 Gaviota fertilizer (made here in Hawaii)

Are you really in hawaii? :o :o :o

cj :)

[valmarg]

m_t_m, I'm not sure, but I don't think the marigolds will be much use against leaf miner.  If you look at the underside of the leaves, you will see small brown bulges in the tracks.  These are the grubs, and a judicious application of the thumbnail should see them off.  Unless your problem is of plague proportions, I think this would be your best method.  Despite looking unsightly, I don't think they do a lot of damage.

valmarg

[tim]

All good fun - but Marigolds or not, we have not had whitefly for 46 years. Is that because we don't use Marigolds?

And do they have to be in flower? 'Yellow puts the bugs off'. If so, how do you time it so that they are always in flower during the tomato season?

If pushed, use 'Eradicoat'?

[saddad]

We use Tagetes for the Greenhouses and have no whitefly.. Calandula edges to the brassica plot made little difference, but looked very nice until the mildew set in. Not hab much whitefly on the Brassicas this year yet... too cold and wet?
 :-\

[torquil]

     has anyone tried basil in greenhouse it realy does work against white fly put it into pots so you can move it about.also  I find if you put out yellow buckets with water in it does attract the black flies then you just keep changing the water.helps keep off sweet peas and flowers.

[valmarg]

All good fun - but Marigolds or not, we have not had whitefly for 46 years. Is that because we don't use Marigolds?

And do they have to be in flower? 'Yellow puts the bugs off'. If so, how do you time it so that they are always in flower during the tomato season?

If pushed, use 'Eradicoat'?

Tim, how many times do you need the above question answering???

For the umpteenth, and final time I will tell you that you plant the marigolds in the same containers as the tomatoes, etc.  The tomato plants take up something from the marigolds that whitefly do not like, therefore thy do not infest the tomato plants.

We acquired whitefly one year when I went to a fuchsia nursery and committed the cardinal sin of putting newly bought plants in the greenhouse.  They had whitefly on them, and within days the greenhouse was infested.

Ever since this infestation we have planted french marigolds in with the tomatoes, cucumbers and chillies.

We may not need to, as we do not seem to have had any whitefly for years, but to belt and brace we always plant the french marigolds in with the tomatoes, chillies, cucumbers.

It is quite probably unnecessary, in the conditions we have at the moment, but I am a great believer in prevention being better than cure!!

valmarg

[HO]

Really interesting. When teaching I conducted trials on companion planting which were statistically indicative of no real protective effect. I have also tried it  at home with little enough effect to stop me doing it again. My sister also found it not much good in her conservatory.  It is possible ,and this I did not do, that  denser marigold planting might produce different results. The problem is the time needed and the scale neede for valid and reliable trials  !!! What I have found that works for me at home is bright yellow pieces of plastic about 45cm X 15cm covered (smeared) with car grease. I use three hung at different heights in my 12 X 8 greenhouse. The plastic came from a Staples self assembly box. The grease lasts several years and catches white fly and unfortunately some other flies. Anyone else tried this?

[valmarg]

HO, no definitely not!!

The 'some other flies' that were caught were most probably hoverflies or bees.

The trouble with the system you mention is that you are likely to catch far more beneficial insects than harmful!!

valmarg