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diseases

Vegetable Garden

12 Garden Pests We Don’t Want To See In Our Veggies

April 30, 2014

Sometime’s it seems there are more bad guys in the garden than good. When we emptied a large strawberry container this week in a HSE garden that caters for adults with intellectual disabilities, we found four of the ten pests listed below in one container alone! When we’re gardening without chemicals it can be a challenge but not impossible to either get rid of, or contain the pests and the first step is identifying the good guys from the bad, something covered a couple of weeks ago with the 12 Friends We Want to See in Our Gardens blog post.

Companion Planting Nasturtiums

Companion Planting Nasturtiums

To identify the pests we need to see them first so the first rule of thumb when dealing with pests organically is vigilance. Check your vegetables regularly, daily if possible and if you spot anything unusual, try to find out what it is and deal with it immediately – it’s very unlikely it will go away on its own.

One of my favourite books to help identify pests and diseases is the RHS Pest & Disease book and I’d recommend it for all gardeners shelves. After vigilance there are several things we can do to prevent a build up of pests, from good soil management, hygiene, crop rotation, companion planting as well as learning pest life-cycles (the weevil below is a case in point), using fresh compost and encouraging beneficial wildlife – all topics covered in my workshops. To help you begin the pest ID, here are a dozen I’ve come across, though there are many more.

Leatherjacket

Leatherjacket – root eating cranefly larvae

1. Leatherjackets

Not the ones we wear, but little grey-brown grubs. Leatherjackets are the larvae of crane fly and are root eaters. They’re fleshy with no legs and can grow as big as 50mm. For more information on how to identify and get rid of them, take a look here.

photo credit: E_Journeys via photopin cc

photo credit: E_Journeys via photopin cc

2. Cutworms

Cutworms are moth larvae that generally live under the soil and are again, root feeders.

They’re larger than the leatherjackets mentioned above and are a green, grey, brown colour about 2.5 cm long. Supernemos are available online if you’ve noticed a particular problem with these grubs or the leatherjackets.

cabbage white caterpillars3. Caterpillars

Cabbage white butterflies and moths start appearing around May and lay their eggs on the undersides of Brassica leaves (kale, cabbage, broccoli). The eggs hatch and the caterpillars feast on the leaves of seedlings you may have lovingly grown, leaving gaping holes and if left unchecked, no leaves whatsoever.

There are a few ways of dealing with caterpillars organically. First of all cover the bed your Brassica are growing in with netting made with holes small enough the butterfly can’t squeeze through to lay her eggs. Make sure the net is fixed to a frame and not sitting directly on top of the plants or the butterfly will lay her eggs through it. If you do spot signs of caterpillars, pick them off the plants and destroy them or move them to a sacrificial plant such as nasturtiums where they can chomp away without damaging your precious leaves.

snails4. Slugs & Snails

I could spend every lesson in every workshop discussing slugs and snails as they’re the bane of gardeners lives! Instead I wrote a blog post that has 15 ways of dealing with them organically and a few more comments have been added to the list. Take a look if slugs & snails are your nemesis.

Carrot Root Fly Damage

Carrot Root Fly Damage – spot the larvae

5. Carrot Root Fly

I think I’d heard about carrot root fly long before we began growing veg but only came across this pest recently. Boy does it do some damage. I won’t go into detail here as I dedicated a blog post to it after we discovered it in Callan community garden, but trust me, you really don’t want this pest in your garden.

aphids7. Aphids

Greenfly, blackly – most of us are familiar with aphids in one guise or another.

They love our roses and they love our broad beans and they breed like mad. Here’s a post all about them with a few suggestions on how to keep on top of them.

spidermite8. Red Spidermite

My polytunnel became so infested with red spidermite last year I had to take everything out and wash the tunnel and everything it contained from top to bottom because the spidermite had infected it all. It was a demoralising experience that I don’t want a repeat of, ever. How did it happen? I took my eye off and didn’t spot them early enough. It was a hot summer and I didn’t keep the polytunnel damp enough – red spidermite thrive in hot, dry conditions. There’s no excuse as I’ve seen infestations a couple of times. Here’s a post about a red spidermite attack we spotted early enough in Goresbridge Community Garden a couple of years ago you might like to look at for tips and suggestions.

weevil grub

photo credit: Scot Nelson via photopin cc

9. Weevils

Whether the weevils are after your legumes as in pea and bean weevil or after your strawberries, as in strawberry weevil, they’re a curse as the distinctive orange headed larvae eat the roots and the adults eat the leaves. The Irish produced Supernemos are said to be effective against strawberry weevils and may well be the answer.

Beet leaf miner10. Leaf Beet Miner

Beet miner’s are maggots that have hatched from fly eggs laid between the layers of leaves. There’s no cure, organic or otherwise, other than vigilance. Once you spot them, remove the infected leaves and the plants will recover. This post explains them in more detail.

Cockchafer (May Bug) aka root eater11. Chafer Grubs

The first time I came across one of these grubs (cockchafer pictured on the left) it reminded me of the enormous widgedeygrubs our children are fascinated with on ‘I’m A Celebrity’.  Almost the size of your thumb they eat roots and once they pupate the cockchafers will become Mays Bugs or Billy witches. We tried watering Supernemos onto the raised beds in Leighlin Parish Community Garden the first year we came across them and didn’t see them again as a result.

12. Gooseberry Sawfly

gooseberry sawfly

gooseberry sawfly larvae

Lots of people were tweeting about gooseberry sawfly larvae damage last year – a caterpillar than can literary strip bushes bare in just a couple of days. They’re also partial to currant bushes which I learnt when they took a liking to our red currant bush. Here’s a post on how to deal with them. I heard a tip recently suggesting laying rhubarb leaves at the base of bushes to deter this fly – something I’ll be trying soon.

There are many more pests and just when we think we’ve seen them all, along comes a new one. Lots of people have mentioned the weevils this year and ants seem to be causing a problem too. Ants won’t damage your garden but they do harvest aphids, a sprinkling of cinnamon or semolina powder seems to sort them out however.  I have a general rule of thumb in our garden – as long as the bugs aren’t trying to eat our vegetables, they can stay.

Have you come across any pests that have had you hopping mad at the destruction they’ve caused?

Green, Vegetable Garden

8 Tips for Managing Potato Blight

August 22, 2012

Potato BlightHere we are, almost at the end of August and three months after first being alerted, still hearing potato blight warnings in Ireland. Not surprising really given the damp warm conditions Ireland has been under for many weeks, but if you’re growing potatoes or tomatoes it’s imperative you keep vigilant.

Blight is tricky to control organically and there’s a lot of confusion about what home growers are ‘allowed’ to use or not.

A couple of years ago I was informed that I could use copper sulphate, which was available as Bluestone in most chemists and that I could make up my own Burgundy mixture (a mix of copper sulphate, washing soda & water).  However, on enquiry at the local pharmacy I was told that they were no longer allowed to sell Bluestone and that it was illegal to make up my own solution, so that scuppered that idea.

Potato BlightWhat can organic growers do to prevent blight affecting crops?

Blight is a parasitic fungus (Phytophthora infestans) that usually attacks in the summer months in humid conditions and is carried on the wind.  It can attack leaves, stems and tubers and can also cause Tomato Blight as tomatoes and potatoes are in the same (Solanacea) family.

  1. The method that has been the most effective in my experience is to plant resistant varieties. Sarpo Miras (an early maincrop), Sarpa Axona (maincrop) and Blue Danube (early maincrop) all show excellent blight resistance. Setanta (maincrop) and Orla (early) are Irish varieties that have shown good resistance too.
  2. Planting early crops of potatoes (new potatoes) will help as the idea is that they will have matured before blight warnings are issued. However, in 2011 warnings were issued mid-May so that can’t always be guaranteed.
  3. Keep earthing up potatoes as they grow (bringing the soil up around the stems). This will help to protect the potato tubers in the ground should blight attack.
  4. When placing the seed potatoes into the soil, use the maximum spacing suggested. This will ensure there’s an airflow between growing plants.
  5. Practice good crop rotation
  6. Good hygiene. Ensure beds are as weed free as possible.
  7. Vigilance. If you notice blight on the leaves, cut the stems at ground level leaving the tubers in the ground for at least ten days before moving them. Unless you have a really hot compost system, you will need to move the foliage away from your site, disposing of it safely. Blight is often recognised by a white furry ring on the underside of leaves that outlines the brown splodge (see top picture).
  8. If none of those methods appeal or you’ve tried them before and they haven’t
    vitax-bordeaux-mixture-175g

    image courtesy The Secret Garden Centre

    worked, Bordeaux Mixture is approved for organic use and can be sprayed onto your crops. (Thanks to @KathyMarsh for the update: Under Irish organic standards you may use up to 6kg per hectare per year. You no longer have to ask permission but must record why you used it.) This is a preventative measure however and should be sprayed before the risk of blight. It’ll be no good whatsoever spraying it on afterwards. Bordeaux Mixture is available from good garden centres or online.

It’s difficult to talk about blight without mentioning the GM potato trials that will going on in Teagasc at Oak Park, Carlow that many of us alarmed by the increase in GM crops are nervous about. I’ve written about GM in previous posts and here’s a link to an excellent article in thejournal.ie explaining that GM crops aren’t just about the science – they’re about the politics.

www.spuds.ie are running an awareness campaign to educate the public about the availability of naturally blight resistant varieties that are available in Ireland. If you’d like to find out more about what they’re doing, please head over to their website, sign up for their newsletter and show them some support.

Have your crops been affected by blight this year? Did you find that planting resistant varieties has helped?

Vegetable Garden

How to Plan Crop Rotation in a Vegetable Garden

March 10, 2011

The Greenside Up Vegetable Garden Crop Rotation
Vegetables crops are grouped into families.  Crop rotation simply means that related annual vegetables are grown together in their families and their positions moved around the plot once a year (or more).

Why use Crop Rotation?

There are a number of reasons for rotating crops:

  •  It helps to prevent pests and diseases that live in the soil.  For example, two major worries in vegetable growing are clubroot disease in Brassica crops (cabbage type plants) and the nematode known as eelworm in potatoes.  If the crops are grown in the same place each year, the chances of these problems occurring are much greater.  By moving them around annually and only growing them in the same ground every four years of so, the pest and disease life cycles should be broken.
  • It stops the soil becoming drained of nutrients that the same plants would use every year.
  • Crops can follow each other that will benefit each other.  E.g., bean and pea roots hold lots of nitrogen.  If their disease free roots are left in the ground once the crops have been harvested, the Brassica that will follow in the next rotation will reap the rewards by producing lots of leafy greens. Also Brassica like soil that’s consolidated so by leaving the legume roots behind and thus causing little disturbance to the soil, the Brassica that follow will root better.
  • If vegetable families are grown together, it’s likely that the soil for each will need to be treated in the same way and that they will be prone to the same pests and diseases so can be treated together easily.

Important Families: (That are likely to be grown outdoors in a cooler climate)

Potato: Potato, tomato
Legumes: Peas, beans
Brassica: Cabbage, broccoli, swede, turnip & radish
Allium: Onion, garlic, shallot, leek
Others: Carrot, parsnip, parsley, and celery

Anything else can be fitted in such as sweetcorn, squashes, salads etc.

Basic Guidelines for Crop Rotation

The main guideline is to keep families together; if a section is to hold more than one family, try to keep those with similar growing requirements together e.g., potatoes and pumpkins like lots of organic matter.

  • Using a bed system can make planning a rotation easier.
  • Take lots of photos and make notes as it’s easy to forget where you grew something a year or to ago.

How to Plan A Four-Year Crop Rotation

The following is a guideline.  You may not want (or need) to follow this rotation at first.  However, after a couple of seasons you may start to wonder what can be planted in the gaps.  This should help with your planning. It’s a popular plan that many people use and has worked well for us.

how to plan crop rotation in a vegetable garden
People Like Bunches of Roses is an acronym I heard recently that may help you to remember the rotation.
Year 1:              Potato crops
Year 2:              Legumes (peas, beans)
Year 3:              Brassicas (cabbage type crops)

Year 4:              Root crops/others.

In this four-year rotation the potatoes and squashes are planted first (Bed 1) as the potatoes break up the soil nicely.

In year 2 the legumes (peas & beans) will be planted in Bed 1 as they will fix nitrogen into the soil for the Brassica (cabbages) that will follow.  Therefore in year 3 the leafy crops (Brassica) will be planted in bed 1 and lastly in year 4 the roots and others can be planted in bed 1 as they are the least demanding of the crops.

You may also find it useful to use a five-year rotation, rotating the Allium (onion) family separately.  Whichever you decide, avoid leaving the soil empty. Either cover it when not in use with carpet or similar or plant a green manure or a crop into it.

Bed 4:  Others (carrots, beetroot, parsnips, celery and sweetcorn,onions, garlic, shallots )Bed 1: (Early, main crop potatoes, pumpkins, courgettes, and tomatoes)

These are the biggest feeders.  In the autumn months (once the root crops have been cleared), apply well-rotted manure or compost or grow a green manure such as grazing rye. In spring, dig in the green manure (grazing rye) and if you didn’t have the opportunity to manure, or have sandy soil, apply manure or compost now, leaving a few weeks between manuring and sowing if you can.  After harvesting the potatoes, plant anything from the legume family.

Bed 4:  Others (carrots, beetroot, parsnips, celery and sweetcorn,onions, garlic, shallots )Bed 2: Legume Family (beans, peas, french beans and runner beans)

The Legumes.  These fix nitrogen themselves so do not require extra manure.  They will benefit from leaf mould mulch once they’ve been planted out however (to improve soil structure).  Once harvested, sow a nitrogen-fixing green manure such as winter tares, check the soil pH and add lime in the autumn if necessary.

Bed 4:  Others (carrots, beetroot, parsnips, celery and sweetcorn,onions, garlic, shallots )

Bed 3: Brassica (cabbage, swede, turnips, broccoli, and radish)

Leafy veg (Brassica & salads) like to follow peas & beans. Dig in the green manures (winter tares) or add compost (or well-rotted manure) in the spring prior to planting.  Mulch with leaf mould in the autumn

Bed 4:  Others (carrots, beetroot, parsnips, celery and sweetcorn,onions, garlic, shallots )Bed 4:  Others (carrots, beetroot, parsnips, celery and sweetcorn

Mostly comprises of root crops but miscellaneous crops fit in well here too. They don’t need much feeding, as they’ll use up everything that’s leftover from previous crops. Apply compost in the spring where Allium, celery, leafbeet and sweetcorn will grow.

Sow a green manure (such as grazing rye) over winter, ready for the potatoes in the spring.

Only One Vegetable Bed?

If you only have one or two small beds, don’t worry. Just divide them into four with bamboo or hazel sticks and plant your vegetable families in the different squares or rectangles.  You may also find that you plant more Allium (onions) than Brassica. It doesn’t matter. As long as you aim to keep the vegetable families apart for as long as possible, you’ll have done your best.

For a very easy to follow and simple visual explanation check out this great video from Monty Don on Gardeners World.

Do you practice this version of crop rotation or a different one? Do you find it works?

Vegetable Garden

Pesticides and Fungicides using kitchen/garden ingredients

June 21, 2010

Lots of people have been asking how to deal with pests and diseases organically recently so I’ve listed below a few ‘recipes’ to deal with most of the common ones.

However, even organic pesticides and herbicides should be used as a last resort, and are generally never recommended for use in polytunnels and greenhouses.

In the long term encouraging a garden full of biodiversity is the aim.  Planting hedges and flowers that will provide hiding places and food for natural predators as well as providing bird boxes and areas with water will all help to create a more balanced environment.

Traps and barriers work well if you put them up early – for instance adding netting will prevent butterflies landing on the brassicas before they become a problem.  Turn a terracotta plant pot upside down, stuff it with straw and balance it on a bamboo stick – this will attract earwigs that can be collected and disposed of easily.

Crop rotation and companion planting should be used too eg moving potatoes to a new area each year will help prevent the build up of potato eel worm and planting alliums and carrots/parsnips together will benefit both species.  Blasting aphids off with a hose or squashing them between your fingers works whilst colonies are small and keeping greenhouses hosed down will help to keep red spider mite at bay. Learning to recognise pests and their cycles is important too. 

However, until you’ve built up the ‘good’ insect population in your garden, you may have to resort to more instant control, so here goes: (its a good idea to test a small amount on a plant 2 or 3 days before use to check that it doesn’t damage the plant).

Pesticides

NOTE: Most insecticides kill beneficial insects as well as their predators so use with caution. It’s often advised to spray in the evening when the beneficial insects will not be as active (for instance if you spray soap to kill greenfly, you may kill the hoverfly larvae that would eventually eat the greenfly).  As with any chemical, organic or otherwise, wear gloves and avoid breathing in the spray.

Insecticidal Soaps – Control aphids, thrips, spider mite
Buy from organic suppliers or make your own:

Soap Spray

2 tbsp (30ml) phosphate free washing up liquid (label may say safe in septic tanks)
2.2 lts water

Avoid spraying in bright sun as it can scorch foliage. Test a few leaves a couple of days before use as it may damage the plant. Will have to repeat every 24 – 48 hrs.

Rhubarb Leaves – All leaf eating insects

Rhubarb leaves are poisonous as they contain large quantities of oxalic acid. Wash vegetables thoroughly that have been sprayed before eating them.

1kg rhubarb leaves (can use tomato, elder or nettle leaves instead)

1lt water

Mix together, leave for a week, strain and use as a liquid spray.

Or

450g rhubarb leaves
1.1lt water

15ml soap flakes

Boil for 30 mins, topping up to allow for evaporation. Allow to cool and add soap flakes as a wetting agent. Strain and use as an undiluted spray.

Elder Shoots – Controls aphids and caterpillars


450g young Elder shoots
3lt water

Mix in large pan and boil for 30 mins. Strain and cool. Can be bottled while hot and will keep for 3 months.

 Cinnamon PowerDeters ants

Sprinkle at the entrance to their nest and they will move away.


Garlic SprayKills many insect pests and friends

Note: Do not use metallic containers with garlic sprays as they may react with the mixture.

1. Non oily version

1-2 garlic bulbs
Boiling water
1ltr soap spray

Chop garlic bulbs and cover with boiling water in a lidded jar. Leave to soak overnight. Strain and add to soap spray. Unused spray will decay but it can be frozen to preserve it.

2. Oily Version

100g chopped garlic

30ml liquid paraffin or baby oil

500ml water

5ml liquid soap (phosphate free)


Soak garlic for at least 24 hours in paraffin or oil in a sealed jar. Add water and liquid soap and stir well to emulsify the oil. This should keep well. Use 30ml of preparation in 500ml to spray plants.

3. Powdered dry garlic bulbs

Sprinkle the powder over affected plants or mix with water to make a spray.

Wormwood TeaControls aphids, caterpillars, flea beetles & moths

225 g wormwood (Artemisia absinthium)
2.25 lts water
1 tsp soft soap

Simmer for 30 minutes, strain and add soft soap and add to spray bottle. Alternatively place dried sprigs beside carrots & onions to mask their scent.

Sulphur – Spider mites, thrips

Fungicides

Fungal infections are usually visible to the naked eye and include mildews, leaf spots and rusts. They are spread by spores. Carefully removing infected leaves immediately they are infected will help to control the infection.

Sodium BicarbonatePowdery Mildew

5g baking soda

1lt water

Mix together for a spray

Or

Blackspot & mildew on roses

3 tsp baking soda
1 heaped tsp soluble fertiliser
Few drops phosphorous free washing up liquid
4.5 lts water

Mix first three ingredients together thoroughly with 200ml water. Add to the remaining water in a watering can. This can be watered over the foliage every two weeks, starting in early spring and continuing throughout the growing season.

Or

Downy mildew

100g washing soda
4 lts water
50g soft soap

Dissolve washing soda in water then add soft soap to a spray bottle


Or

Powdery mildew, blackspot

20g baking soda
15ml citrus oil
2.2 lts water

Mix and spray foliage lightly, including the undersides. Do not pour or spray this mix directly into the soil.

Milk – Mildew

300ml milk
700ml water

The enzymes of fresh milk sprayed on plants will attack mildew. A stronger solution will result in a foul smell as the milk goes rancid.

Elder SprayMildew and black spot

Same as pesticides:

450g young Elder shoots
3lt water

Mix in large pan and boil for 30 mins. Strain and cool. Can be bottled while hot and will keep for 3 months.

Dock SprayMildew

15g mature docks
1 lt water

Puree docks and mix with water. Leave to soak for an hour and spray.

Garlic SprayFor scab, mildew, bean rust & tomato blight.

See pesticide preparation above.

10g crushed garlic or – Powdery mildew.

15g crushed onions
1lt water

Horsetail – Mildew on crops and some rusts, eg., celery

Preventative against potato blight.

28g horsetail (can use all parts of the plant, including rhizomes)
1 lt water
Mix together and allow to stand for 24 hours. Strain and use undiluted as a spray.

Finally:

DISCLAIMER: The control methods are suggested here as a matter of general information. Under Irish and EU law it is illegal to use any preparation as a pesticide/fugicide/herbicide that is not approved for such use. The author and the website accepts no responsibility for how a user may mix, use, store, or any effects the mixture or its elements may have on people, plants or the environment. The information here is for reference only and does not imply a recommendation for use. If you disregard this warning and make any of the preparations, you do so entirely at your own risk.

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Lifestyle

My Favourite Gardening Books

February 6, 2010

In my quest to keep learning as much as possible about growing fruit and veg I’m always on the look out for good gardening books. There are so many out there it can be difficult to choose which ones to spend our hard-earned cash on.  I’d planned to make this a blog of my top five but found some of them really hard to weed out (couldn’t resist).   The following are therefore my current favourites.  If anybody has any comments, recommendations or further suggestions I’d love to hear them.

This week I’m raving about my latest buy:

“How Does Your Garden Grow” by Chris Beardshaw (published 2007 Dorling Kindersley). 

This is a fantastic book for anybody who wants to learn a bit more about the science of plants and soil, written and laid out in an easy to read fashion with sketches, photos and anecdotes from Chris’ own experiences.  Covering topics ranging from plant cells, light and shade through to seasons and ageing, the book covers all the basics of horticulture. I can’t recommend this enough for anybody who wants to learn more about the gardening world, subsequently helping them to improve their skills.

Grow Your Own Vegetables by Joy Larkcom (paperback published 2002 Frances Lincoln Ltd).

A guru of fruit and veg, Joy shares her knowledge in this handy sized book packed full of practical information on everything you need to know about growing vegetables.  A no-nonsense book (there are no glossy photos to be found here) Joy covers all aspects of growing from site, sowing, planning as well as a comprehensive vegetable directory.  I wish I’d known about this book when I started out.

The New Self-Sufficient Gardener by John Seymour (published 2008 by Dorling Kindersley).

We were bought the original Complete book of Self-Sufficiency as a wedding gift and have often referred to it over the years (although sadly not living by it yet!).  The new Self-Sufficient Gardener is a beautifully illustrated guide to producing your own food.  More general and basic than Chris Beardshaw’s book in terms of science, John covers the important topics such as the ecology of soil, the edible parts of plants as well as gardening through the year and planning a food-producing garden organically.

The Plant Propagator’s Bible by Miranda Smith (published 2009 by The Reader’s Digest Association).

If you’d love to grow your own plants from seeds, cuttings or division but aren’t sure how, this book has it all.  Taking you step by step with illustrations and photo’s on many propagating techniques, including grafting, budding and layering, this book will save you heaps of cash as you start rearing your own young plants.

The RHS Pests & Diseases – The Definitive Guide to Prevention and Treatment by Pippa Greenwood & Andrew Halstead (published 2009 by Dorling Kindersley).

A long title but the best book I’ve found to date on pests and diseases.  This book has a gallery of colour photos that help to identify problems, as well as a comprehensive A – Z of pests, diseases and disorders, including the symptoms, cause and control of each problem.  Although we garden organically, the section on chemicals made interesting reading and the chemical-free and biological control chapters covered many of the methods used by organic gardeners.

The Vegetable & Herb Expert by Dr D G Hessayon (published 2002, Transworld Publishers).

This was my first gardening bible and one that was carried to my plot every time I ventured out. I was also given a diary version of this by a close friend but for some reason keep losing it!  Although the pages are now falling out I think it’s a must have for beginners, containing illustrations of recommended seed sowing distances, expected yields and soil preparation for each crop.  The only downside I’ve found with it is that some of the varieties recommended haven’t always been available in the garden centres (so if you do use it to help you choose a variety suitable for your garden, make sure you write down a second and third choice too!)

The Garden Expert by Dr D G Hessayon (published 2005, Transworld Publishers). A

nother handy Hessayon book, this introduction to gardening covers many aspects including putting a name to your soil, improving drainage, digging, fertilising and liming amongst many things.  A useful reference book, particularly when starting out.